Lord Wilson of Dinton hit out at the prime minister for acting like “an angel of the Lord bringing glad tidings about the birth of Christ”, when the agreement was finally signed.
Critics have pointed out huge gaps that threaten the livelihoods of professionals whose qualifications will no longer be recognised in the EU and the absence of a deal for the City of London.
It was already inevitable that traders face a mountain of costly new red tape from 1 January, requiring them to fill in 200 million new customs forms for example.
Lord Wilson said: “Did the prime minister, presenting his Brexit treaty to the nation, really compare himself implicitly to an angel of the Lord bringing glad tidings about the birth of Christ?
“His treaty merely retrieves a small portion of the great political and economic benefits we enjoyed as members of the EU.
“It does not resolve the issue of our place in Europe and the world, which nearly half of the British people would have preferred to continue to be in Europe. The combined damage of Brexit and the coronavirus will be with us for decades to come.”
In a letter to The Times, Lord Wilson added: “Boris Johnson is just an Amazon driver with a modest package.”
The criticism comes amid rising anger that the government has “betrayed” the fishing industry by failing to gain control of stocks in UK waters, as it repeatedly promised.
The UK conceded to the EU’s demand to give up only 25 per cent of the value of its catch, at the end of a five-and-a-half-year transition – setting the scene for a future bitter dispute.
Lord Wilson, a crossbench peer, was head of the civil service under Tony Blair, from 1998 until 2002 and, before that, head of the economic secretariat under Margaret Thatcher.
The criticisms came as Brexit trade deal moved a step closer to being passed, with unanimous approval granted by EU member states.
Germany’s spokesman hailed the “green light” after their ambassadors backed a provisional application of the agreement, struck on Christmas Eve.
The move means the agreement can come into operation on New Year’s Day – even though the European Parliament will not give its approval until February.
On Wednesday, the House of Commons is certain to back the agreement, with Labour voting in favour alongside the government, despite its sharp criticisms of the “thin” deal.
