Mr Cameron, 54, who resigned as Prime Minister in 2016 after Britain voted to leave in the referendum which he ordered, broke his silence on Twitter after the good news emerged on Thursday.
He said the deal was ‘very welcome’ and a ‘vital step’ in forging a new relationship with the EU.
Current PM Mr Johnson made history by agreeing a trade deal in record time to avoid a No Deal Brexit which would have come into force when the transition period ends on January 1.
Mr Johnson said in a press conference on Thursday afternoon he hoped the package would pave the way for a ‘new stability and a new certainty in what has been a fractious relationship’.
Former Prime Minister David Cameron today congratulated the UK’s negotiating team after Boris Johnson declared that a Brexit deal has been done with the European Union
Mr Cameron, 54, who resigned as Prime Minister in 2016 after Britain voted to leave in the referendum which he ordered, broke his silence on Twitter after the good news emerged on Thursday
Expressing his congratulations, Mr Cameron wrote: ‘It’s good to end a difficult year with some positive news.
‘Trade deal is very welcome – and a vital step in building a new relationship with the EU as friends, neighbours and partners. Many congratulations to the UK negotiating team.’
Mr Cameron first promised a referendum on Britain’s EU membership in 2013, ahead of the 2015 General Election.
After victory in the election, Mr Cameron confirmed the referendum would take place after a period in which he re-negotiated Britain’s relationship with the EU in the hope it would help the Remain side win the referendum.
He declared in 2016 that he had negotiated a deal which gave Britain ‘special status’ and confirmed he would campaign for Britain to remain in the bloc.
However, after a divisive referendum in which Mr Johnson and Michael Gove, who was then the Justice Secretary, opted to back the Leave campaign, Mr Cameron ended up on the losing side.
Current PM Mr Johnson made history by agreeing a trade deal in record time to avoid a No Deal Brexit which would have come into force when the transition period ends on January 1
Britain voted by a margin of 52 per cent to 48 per cent to leave on June 23.
The next day, Mr Cameron said he would resign because Britain needed ‘fresh leadership’. He was then replaced by Theresa May.
A senior Number 10 source said of Thursday’s news: ‘Everything that the British public was promised during the 2016 referendum and in the general election last year is delivered by this deal.
‘We have taken back control of our money, borders, laws, trade and our fishing waters.
‘The deal is fantastic news for families and businesses in every part of the UK. We have signed the first free trade agreement based on zero tariffs and zero quotas that has ever been achieved with the EU.’
EU chief Ursula von der Leyen told her own briefing in Brussels that the terms were ‘balanced’.
‘We have finally found an agreement. It was a long and winding road but we’ve got a good deal to show for it,’ she said.
Mr Cameron first promised a referendum on Britain’s EU membership in 2013, ahead of the 2015 General Election. He then resigned in July 2016 after Britons voted to leave the bloc the month before. Pictured: Mr Cameron with his wife Samantha and their children on the day he resigned
She said the EU had protected its single market, and achieved ‘five-and-a-half years of predictability for our fishing communities and strong tools to incentivise’ for access to continue afterwards.
Ms von der Leyen said her overriding feeling was relief. ‘Parting is such sweet sorrow,’ she added.
Referencing one of his mantras from the talks, Mr Barnier said: ‘The clock is no longer ticking.’
Irish Taoiseach Micheal Martin described the deal as the ‘least bad version of Brexit possible’.
The Fianna Fail leader said: ‘There is no such thing as a ‘good Brexit’ for Ireland. But we have worked hard to minimise the negative consequences.’
German Chancellor Angela Merkel said she was ‘confident’ that the deal was a ‘good outcome’ as it now goes over to EU member states to agree.
For French President Emmanuel Macron – often portrayed as a bogeyman by the British tabloids – ‘Europe’s unity and firmness paid off’.
German Chancellor Angela Merkel, pictured, described the outcome as a ‘good deal’
Spanish Prime Minister Pedro Sanchez welcomed news of the agreement, but insisted the issue of Gibraltar has yet to be settled.
The flow of goods and people across the border risks disruption from 11pm London time on January 31 when the transition agreement ends.
Writing on Twitter, Mr Sanchez said: ‘Spain and the United Kingdom are continuing dialogue to reach an accord on Gibraltar.’
Madrid, London and Gibraltar have been working out the status issues separately from the 10 months of Brexit trade negotiations that finally ended Thursday’s deal.
‘For us… the clock is’ still ticking,’ said Gibraltar government chief Fabian Picardo, while adding that he was ‘optimistic that we will be able to finalise that agreement’.
A US State Department official said: ‘We support the UK in its sovereign decision to depart the EU, and we look forward to continued strong relationships with both the UK and EU.
‘The United States is committed to negotiating a comprehensive free trade agreement with the UK.’
Labour leader Sir Keir Starmer has said the party will vote in favour of the Government’s ‘thin’ EU deal, saying that no deal is simply not an option.
Sir Keir Starmer said Labour will back Boris Johnson’s ‘thin’ EU deal as it was better than no deal
The fervent pro-European said it was ‘in the national interest’ to support the agreement despite concerns over the terms negotiated by the Government.
Sir Keir said: “At a moment of such national significance, it is just not credible for Labour to be on the sidelines.
‘That is why I can say today that when this deal comes before Parliament, Labour will accept it and vote for it.
‘But let me be absolutely clear – and say directly to the Government – up against no deal, we accept this deal, but the consequences of it are yours.’
He said no deal would lead to ‘devastating’ social, economic and political consequences, and said it was not right for Labour to abstain.
Number 10 said the terms meant the UK will not be in the ‘lunar pull of the EU’.
‘We are not bound by EU rules, there is no role for the European Court of Justice and all of our key red lines about returning sovereignty have been achieved,’ the source said.
‘It means that we will have full political and economic independence on 1st January 2021.’
The confirmation had been repeatedly put back as the sides argue ‘fish by fish’ over the rules, with Ireland warning of a ‘hitch’, even though UK sources insisted there are ‘no major issues’.
But the battle to sell the package to voters and Tory MPs is in full swing, as Mr Johnson rings round restive backbenchers.
An internal government assessment insisted that the UK ‘won’ on 43 per cent of the major issues in the £660billion package, compared to 17 per cent where the EU came out on top.
France’s President Emmanuel Macron, pictured said ‘Europe’s unity and firmness paid off’
There will be zero-tariff, zero-quota access to the EU single market – and Mr Johnson has maintained the ability to diverge from Brussels standards, with no role for the European Court of Justice.
The document boasts that concessions were secured on rules of origin for goods, customs streamlining and ‘trusted trader’ schemes, while the financial services sector has been ‘insulated’.
A deal will also avoid huge disruption on top of the coronavirus crisis.
However, the UK looks to have given ground on fishing rights, and secured little succour for the services sector.
For its part, France has started boasting that Mr Johnson made ‘huge concessions’ on fishing in the last stages as the mutant coronavirus variant underlined the vulnerability of UK borders.
The challenge the PM faces was underlined as Tory Brexiteers vowed to put together a ‘Star Chamber’ of experts to scrutinise the documents over Christmas.
MailOnline understands that Mr Johnson was ‘very straightforward’ and did not try to give a ‘hard sell’ in his call with senior MPs.
One MP said subject to seeing the full text the outline was ‘what we hoped’. ‘Maybe it will be a happier Christmas after all,’ they suggested.
Nigel Farage accused Mr Johnson of ‘dropping the ball’, although he also stressed that it was ‘progress’ and the Brexit ‘war is over’. There are fears that political ‘landmines’ in the text will inevitably be uncovered.
The FTSE 100 rose 20 points to 6,516 – 0.3 per cent – on opening amid optimism about a deal. The pound had already gained around 0.6 per cent against the dollar, and 0.4 per cent against the euro overnight.
Sinn Fein President Mary Lou McDonald welcomed the deal between the UK and the European Union.
She said: ‘Four and a half years ago the north of Ireland voted to remain, but despite the wishes of the people it now finds itself outside of the European Union as a result of’ a Tory inspired Brexit.
‘There will be relief that a trade deal has now been agreed between Britain and the EU and special arrangements for Ireland, encapsulated in the Irish Protocol, will be implemented.
‘The Good Friday Agreement has been protected, there will be no hardening of the border and protections for the all-island economy are in place. There is also a level of certainty for businesses.
‘But we are under no illusions that there is no good Brexit for Ireland, north or south, and the full consequences of this are as yet unknown.’
Ms McDonald warned ‘this is not the end of the road’.
She said: ‘EU leaders have accepted the unique position of Ireland and have agreed that the north will automatically become part of the EU in the context of a United Ireland.
‘So we need to start the planning and we need to start talking about a future beyond Brexit.’