LONDON (Reuters) - Workers in Britain marginally back remaining part of the European Union with 45 percent in favour of Britain's continued membership, according to a poll published on Friday.
Of the 1,004 part-time and full-time employees surveyed, 41 percent favoured leaving the European Union, with 14 percent unsure, according to polling company Survation.
Prime Minister David Cameron has pledged to hold an in-out referendum by 2017 amid pressure from some Conservative lawmakers and rising public support for the anti-EU United Kingdom Independence Party.
UKIP pushed Cameron's ruling Conservatives into third place last week in a closely-watched election in southern England triggered by the resignation of a former minister.
The poll, conducted for the largely trade union-backed organisation, Unions21, showed 74 percent of workers were worried an EU withdrawal could see the loss of employment rights in areas such as working hours, discrimination and annual leave.
"Any move to repatriate powers can only be but a smokescreen to take these EU rights away from working people, and make them work longer hours for less pay," said Lesley Mercer, president of the TUC, the umbrella body of most British labour unions.
A previous Survation poll conducted in January showed 54 percent of people support leaving the EU with only 36 percent prepared to vote in favour of continued membership.
Promising to renegotiate Britain's membership terms, Cameron in January told parliament that when it came to employment, social and environmental legislation, "Europe has gone far too far".
(Reporting By Costas Pitas Editing by Maria Golovnina)