Eurosceptic David Campbell Bannerman branded the trio of high-profile europhiles “Britain’s three stooges” after they travelled to Brussels to meet the EU’s chief negotiator Michel Barnier.
He told express.co.uk the group had “no business in seeking to undermine the Government’s negotiating position” and accused them of putting Europe’s interests before those of their own country.
Yesterday Mr Clegg, flanked by Labour peer Andrew Adonis and veteran Tory backbencher Ken Clarke, made an incendiary intervention into the Brexit negotiations by holding talks with a series of top EU officials.
They held meetings with Mr Barnier and the bloc’s financial affairs chief, Pierre Moscovici, at the Commission’s Berlamyont headquarters in scenes which infuriated leading eurosceptics.
Top Brexiteers accused the trio of attempting to “undermine” Mrs May in Brussels by making her look weak and even leaking details of Britain’s negotiating strategy to the EU side.
Eurosceptics have long feared a “Remainer coup” where prominent europhiles try to sow division in Westminster and Brussels to topple Theresa May and pursue a soft Brexit or even reversal of the referendum.
And a furious Mr Campbell Bannerman said: “I think this initiative from these die hard Remainers – Britain’s three Stooges – is sinister and treasonous.
“As a serving member of the party of Government Ken Clarke has no business in seeking to undermine the Government’s negotiating position.”
He branded them a “threat to our democracy” and added: “The British people should see this for what it is. The loyalty of these three stooges is clearly to the greater European project and not to their own country Britain.”
Asked whether he was in Brussels to overturn the referendum result, Mr Clegg laughed and cheerily replied: “If only it were that easy. We’re here just to get a better understanding of what’s going on in the talks.”
He self-deprecatingly referred to the trio as “the rebels” whilst Mr Clarke, often a lone Tory rebel over Europe since the referendum result, joked they were in the Belgian capital to “talk about cricket”.
But the meeting sparked consternation amongst senior eurosceptics who described it as a “distraction” from the real negotiations and questioned why Mr Barnier has only met with Remainers so far.
Independent MEP Steven Woolfe told express.co.uk: “This looks extremely suspect. It is a deliberate, underhanded attempt by a group of Remainers to undermine the official negotiations being conducted by the David Davis and the leave vote last year.
“Frankly, it’s a distraction and is certainly not done in the interests of the UK, but rather in the interests of themselves.”
Former Ukip leader Nigel Farage added: “It’s like an Unholy Trinity going down and desperate to undermine the democratic Brexit vote. Especially so, as Clegg has no electoral mandate.
“That Michel Barnier is even meeting them shows those in Brussels cannot be trusted in these negotiations at all.”
And Ukip MEP Gerard Batten said: “This is outrageous. None of these men are currently elected to anything and have no right to pretend to represent the British public is this matter.
“Having them go to Brussels is like Oswald Mosely and Lord Haw-Haw going to Berlin to negotiate peace terms in 1940”.
Mr Woolfe has now written a letter to the chief negotiator demanding an audience with him for a senior group of Leave campaigners to help “balance out” any perception he is helping those trying to overturn the referendum result.
EU officials justified the meeting by saying that the three Remainers had requested it and that Mr Barnier’s “door is always open for people who want to speak to him and his team across the political spectrum”.