Tory lawmakers are to back an amendment calling for restrictions on the Eastern European migrants out of fears that the party is losing ground in the European elections in May.

On Thursday Tory rebels are expected to support an amendment to the immigration bill calling for restrictions on the Eastern European migrants to be reinstated until 2018.

The move reflects a fear that the party will lose ground to the UK Independence Party in the European elections later this year, analysts say.

The Labour party is forecast to garner 32% of the vote, UKIP will get 26% and the Conservatives would trail third with just 23%, according to a YouGov Plc (YOU) poll commissioned by the Sun newspaper Jan. 16.

On Thursday Tory rebels are expected to support an amendment to the immigration bill calling for restrictions on the Eastern European migrants to be reinstated until 2018.

The move, which is expected to be supported by more than 50 Tory MPs, will come three days after Prime Minister David Cameron gave his first verdict on the immigration levels from Bulgaria and Romania since the start of the year, conceding that they are "reasonable".

Cameron spoke on the numbers coming to the UK from the two countries following warnings last year of a possible "invasion".

But rebel MPs have voiced concerns about the number of arrivals over a long period and want Cameron to add new restrictions to the government's Immigration Bill, which is returning to the Commons on Thursday.

Shadow Home Office minister David Hanson said Labour would support a group of amendments aiming to enable the government to impose further transitional immigration controls on future EU accession countries.