“As representatives of some of the UK’s largest businesses and employers, we believe that British business needs a government at Europe’s top table,” it says.

“We call on all parties to campaign on the basis that the UK must play a central and positive role in the EU.”

Signatories include Virgin Group founder Richard Branson, utility firm Centrica Chairman Roger Carr and British telecom carrier BT Chairman Mike Rake, Shah said.

International Labour Organisation statistics recently showed Britain’s jobless rate had hit a 14-year high, while the budget deficit is set to rise to almost 12 percent of GDP this year.

Prime Minister Gordon Brown, leader of the ruling centre-left Labour party, main rival David Cameron, leader of the centre-right Conservatives, and Nick Clegg, who heads the third largest party – the Liberal Democrats, are likely to clash on Europe during the televised pre-election debate.

The letter is intended to be non-partisan, Shah said.

Britain joined the EU’s forerunner, the EEC, in 1973, but many Britons remain hostile to European integration.

The Lib Dems are the most pro-European of the three parties. Labour are broadly pro-European, while the Conservatives oppose moves towards a federal Europe and want to repatriate some powers from Brussels.

Cameron has said he would try to negotiate the return of Britain’s opt-out in some areas of EU social and employment law, claw back powers on criminal justice and win a complete exemption from the EU’s charter of fundamental rights.

The right-wing anti-European UK Independence Party is also contending the election. Although small, the party stunned mainstream politics when it came second nationally in last year’s European elections winning 13 seats.