LONDON A group of parliamentarians from Prime Minister David Cameron's governing Conservative party on Monday set out their case for Britain remaining a member of the European Union, emphasising benefits including jobs and trade.
The move highlights the difficulties Cameron faces in satisfying all sides of a party deeply divided over Britain's ties with Europe - a subject which has plagued the Conservatives for decades and played a part in the downfall of two of his predecessors, John Major and Margaret Thatcher.
Under pressure from eurosceptics in his own party and the UK Independence Party (UKIP), which has no seats in the lower house of the national parliament but looks set to do well in the European elections in May on a campaign to leave the EU, Cameron has promised to reshape Britain's ties with the 28-nation bloc.
He has also promised to give Britons a vote on whether to leave the EU if he wins next year's national election.
On Sunday, Cameron outlined the areas in which he planned to reform Britain's relationship with Europe, including seeking to prevent mass migration and EU interference in police and judicial matters.
The European Mainstream group, which argues Britain's national interest is best served by working for change within the EU, believes the Conservatives should campaign to stay a member in any future in/out referendum.
Their report, written by 18 Conservative members of parliament including several former ministers, covered topics including the single market, migration, energy and defence and called on the party to better communicate the benefits of EU membership to voter.
"We need to start making the basic economic case that we are Better Off In," wrote Damian Green, minister for policing and criminal justice.
"Conservatives have a big and important case to make, not just about the need for reform, but about the need for Britain to continue to play a leading role in Europe."
Last week opposition Labour leader Ed Miliband said that a future Labour government was unlikely to hold a referendum on Britain's membership of the EU this decade, lowering the chances of Britain leaving the bloc.
Opinion polls show that about 40 percent of British voters want to stay in the EU, with about the same proportion wanting to leave, though they also show widespread hostility to immigration and dissatisfaction with established political parties.
(Editing by Alison Williams)