Gordon Brown's chances of remaining prime minister were receding as his party was humiliated in the European Parliament elections.

By Chris Fisher, Political editor and Shaun Lowthorpe

Gordon Brown's chances of remaining prime minister were receding last night as his party was humiliated in the European Parliament elections, and a cabinet colleague suggested he could be persuaded to step down to save it.

Labour's solitary MEP in the eastern region, Richard Howitt, held on, winning the fifth of its seven seats - which are won on a proportional basis. The Tories kept three of them with Geoffrey van Orden, Robert Sturdy and Vicky Ford, Ukip two (the second of which went to Norfolk farmer Stuart Agnew along with David Campbell-Bannerman) and the Liberal Democrats one with Andrew Duff re-elected.

Labour came in fourth in the region as a whole, but was reduced to fifth place in parts of rural Norfolk and was reported to have finished third in Norwich behind the Greens and the Conservatives.

Nationally, Labour also looked to be in grave danger of finishing behind Ukip as well as the Tories. It also seemed that its share of the vote would plunge well below 20pc - adding greatly to the pressure on Mr Brown to quit.

In the eastern region, Labour's share of the vote fell to a mere 10.5 pc - a drop of almost six percentage points on the last European elections in 2004. The Tories won 31.2pc of the votes, Ukip 19.6pc and the Lib Dems 13.8pc.

The first official regional results, for the north east, were also deeply ominous for Labour - showing a nine percentage point drop in its share of the vote. In 2004 it won 34pc of the vote in that heartland region and 22.6pc nationally. Its 25pc share in that region this time suggested its national share of the vote would end a long way under the 20pc mark.

That, it was suggested yesterday, could be the final straw for many Labour MPs, and could persuade them to join a move to force Mr Brown out of office.

Before the election results, the PM had already been rocked by a statement by cabinet office minister Tessa Jowell that he would quit if he came to the conclusion that he was an obstacle to the party's recovery.

In a separate blow to Labour, the British National Party last night won a seat in the European Parliament for the first time in its history after receiving 120,139 votes in the Yorkshire and Humber region.

Even in the wake of the Euro-hammering, Mr Brown can be expected to dig in and strongly resist that idea - and will be furious that Ms Jowell, just two days after returning to the cabinet, spoke in such terms.

He defiantly stressed yesterday that he has no plans to hand over the reins. Speaking at a meeting of Labour activists in east London, he declared: 'What would people think of a Labour government faced with an economic crisis ... if ever we walked away from them at a time of need? We are sticking with them and working with them.'

But he faces a potentially fatal meeting today of the Parliamentary Labour Party (PLP). If many backbenchers, with the Euro-poll results ringing in their ears, tell him that he is a large part of the problem rather than the solution, he could be forced out of 10 Downing Street later in the week.

Reacting to the result, Conservative Geoffrey van Orden said: "I'm delighted, in absolute terms our vote is up and we have three candidates elected. I'm disappointed we didn't get a fourth seat, but given what's been happening everywhere, I'm not surprised by that. The significant thing is the reduction in the Labour vote"

Andrew Duff, said he was pleased the Lib Dems had boosted its vote and overtaken Labour. "It's a good thing for this region that there is a committee pro-European electorate."

Labour's Richard Howitt said: "I'm relieved - I didn't know coming in here what the result would be. Labour has a core of support who share our values and our principles and I wish to express my sincere gratitude to people who chose to help me be re-elected.'

Rupert Read said he was devastated by the result but he took heart at the surge in support.

"We were the big gainers on the night in terms of vote share, and that bodes well for the forthcoming Norwich North by-election."

See the EDP for Euro election results, reports and reaction.