Tesco chief executive Sir Terry Leahy has been asked by Democratic presidential candidate Barack Obama to meet with and engage with American trade unions.

In a letter to Leahy, Obama “strongly requests” he enters in to dialogue with unions, which are seeking recognition at its US chain, Fresh & Easy.

Obama said in the letter: “It is in your interest to ensure that the communities and the leaders of workers in the industry are heard and that their concerns are heard and respected.”

It is the second time that Obama has approached Tesco on behalf of the United Food and Commercial Workers’ Union about the issue.

He first wrote to Fresh & Easy chief executive Tim Mason before the first store opening of the US chain eight months ago.

According to the Times, Tesco has signalled that it won’t shift its position on the issue. A Tesco spokesman said: “We strongly believe that union membership is a matter of individual choice and if our people want to join a union, then they can and will. All the signs so far are that there is little interest in doing so.”

Tesco’s AGM will take place in Birmingham tomorrow.