* Immigration a hot political topic in Britain
* Senior MP accuses Tesco and Next of shunning UK workers
* Retailers deny unethical or illegal practices
By Andrew Osborn
LONDON, Aug 11 (Reuters) - Britain's opposition Labour partyis to accuse supermarket giant Tesco and clothingretailer Next of turning away British workers wherepossible to exploit cheaper migrant labour.
In a speech that will drag the firms into apolitically-charged immigration debate ahead of a 2015 election,senior Labour lawmaker and immigration spokesman Chris Bryantwill accuse the companies on Monday of deliberately excludingBritish people.
"It is unfair that unscrupulous employers whose onlyinterest seems to be finding labour as cheaply as possible, willrecruit workers in large numbers in low wage countries in theEU, (and) bring them to the UK," Bryant will say, according toadvance extracts of his speech.
Polls show immigration is one of the subjects that worriesBritish voters the most and any perception that retailers aredeliberately disadvantaging locals could damage Prime MinisterDavid Cameron's Conservatives as well as the firms themselves.
Cameron is trying to stop an exodus of voters to theanti-immigration UK Independence Party before the 2015 vote.
Bryant will accuse Tesco of favouring workers from EasternEurope over British ones and of relocating one of itsdistribution centres in a way that discouraged local employeesto continue working for the firm.
He will also accuse Next of bussing in workers from Polandto skirt British labour laws that would make hiring comparablelocal workers more expensive.
Next said in a statement on Sunday it did hire Polishnationals to work in Britain at busy times, but said it did sobecause it couldn't find enough Britons to fill vacancies andthat it was not doing anything unethical or illegal.
"Mr Bryant wrongly claims that Polish workers are used tosave money. This is simply not true," it said. "We are deeplydisappointed Mr Bryant did not bother to check his facts withthe company before releasing his speech."
Tesco could not be reached, but a Tesco spokesman told TheSunday Telegraph newspaper it was wrong to accuse thesupermarket giant and that it tried hard to recruit local peoplewhere possible.
Bryant's intervention comes as Labour's opinion poll leadover the Conservatives narrows and its leader Ed Miliband facescriticism from colleagues for what they see as a failure tocommunicate the party's policies clearly or strongly enough.
"We're not suggesting any law has been broken," a Laboursource told Reuters. "Tesco and Next are anecdotal examples,"the source added, saying the party wanted to spotlight theproblem so it could be solved.
Separately, Labour cited research that showed Britain hadseen one of the biggest falls in real wages of any EU countrysince 2010.