David Cameron faced another blow as Tory pollster Lord Ashcroft said his research suggested Labour could achieve a "comfortable working majority" at the General Election.

The Tory party faces a "very uphill struggle" to counter the core Labour support, bolstered by left-leaning Liberal Democrats who have drifted away since the coalition Government was formed.

Lord Ashcroft said the Prime Minister's best hope was to win over a "coalition of the willing" who are prepared to accept further austerity on the basis it will benefit the country and their families in the long run.

The former Tory treasurer's latest research examined 22 key seats, either held or targeted by Nick Clegg's party, to see which way they would fall in May.

His findings indicated that the Tories would win eight seats from the LibDems - but that Labour would also take the same number from the Lib-Dems.

Meanwhile, Ukip defectors "reckless Reckless" and "kamikaze Carswell" risk helping Labour leader Ed Miliband into Number 10, a senior eurosceptic Conservative has warned.

Former Tory deputy chairman Bernard Jenkin said ex-MPs Douglas Carswell and Mark Reckless were impatient and had "kicked the table over" by deciding to join Nigel Farage's Ukip.

The Harwich and North Essex MP also called on the Prime Minister to unite the Tories and the country by clearly outlining the party's approach to the European Union in their 2015 General Election manifesto.