Labour...recognises that immigration can have a negative effect on British workers...Labour's immigration spokesman...said the party had "concerns about immigration, the pace of migration, the undercutting of workers' terms and conditions and the effect on the UK labour market"...[T]he speech was overshadowed by confusion over...criticism of Tesco and Next for their use of non-UK workers. He had briefed...that the two chains were examples of "unscrupulous employers" that favoured foreign labour over British workers...But he backtracked...saying the companies were examples of "good employers" that tried hard to recruit UK workers but found it difficult to find staff with the right skills.