29/04/2014 07:56 BST | Updated 29/04/2014 08:59 BST

Ukip Could Gain Votes Of One Third Of Conservative Party Members

ADRIAN DENNIS via Getty Images
UK Independence Party (UKIP) leader Nigel Farage poses for a picture at the Portsmouth Guildhall on April 28, 2014. Farage visited Portsmouth on a campaign tour ahead of the European elections in May. AFP PHOTO / ADRIAN DENNIS (Photo credit should read ADRIAN DENNIS/AFP/Getty Images)

More than a third of Conservative Party members are considering voting for Ukip at the upcoming European elections, lead to a dangerous hollowing out of David Cameron's election machine, according to research published today.

The data compiled by Queen Mary University of London and the University of Sussex suggests Cameron's chances of winning the next election could be seriously undermined not just by 2010 Tory voters switching the Ukip, but by the defection of actual members of his party.

The research also found that it was Conservative members with more left wing views on the economy and more right wing views on social issues that are most tempted to vote Ukip.

Co- author professor Tim Bale said: "Members may be more ideological than most voters; but if they don’t feel they’re getting what they want from leaders who they can’t identify with, then – just like more and more voters these days – they prepared to take a punt on what they see as a more attractive alternative.

"This really challenges our assumptions about grassroots members in Britain and other countries. The common wisdom says that they’re a guaranteed source of votes for their party. But it looks like a combination of policy concerns and ideological differences with their leader can trump their institutional loyalty."

The three other main parties have stepped up their attacks on Ukip as polling day draws near. On Tuesday The Guardian reported on a cross-party campaign to condemn Nigel Farage's party as racist to be launched this week.

Ukip has been under pressure after several of its members, including the face of its election campaign video, were revealed to have made deeply controversial comments about race. One Enfield council candidate, William Henwood, suggested the comedian Lenny Henry leave Britain to live in a "black country".

However the scrutiny does not appear to have damaged support for Farage's party - with Ukip expected to come first in the European elections.

Professor Bale and his co-author professor Paul Webb said many Tory members do not feel "valued or respected" by their own party leadership and regard Cameron as ideologically remote from them.

"Members defecting to UKIP – even those voting for, rather than joining the party – may erode the Conservatives’ resources in the form of party subscriptions or fewer members to drum up support among less committed supporters in the electorate," professor Bale said.

"Voting for Ukip could be the first step on a road that sees some Tory members eventually joining Nigel Farage’s party. That might provide Ukip with a stream of experienced activists who could boost its already effective insurgent campaign. If that happens, the next general election is going to be very difficult indeed for David Cameron."