Labour's deputy leadership candidates are attempting to draw a line under the unpopularity of Tony Blair's close relationship with George Bush, as they lay out their plans for renewing the government.

In a survey published by the Guardian today, cabinet ministers and other contenders criticised the record of the Bush administration on everything from Guantánamo Bay to climate change.

With only days to go before nominations close, the Guardian asked the six Labour politicians hoping to inherit John Prescott's job to answer readers' questions on key issues. Most offered critiques of the US, demonstrating the party's keenness to reconsider foreign policy. Peter Hain, Northern Ireland secretary, said: "The challenge has been how we work with a very rightwing president ... We must pursue a progressive internationalist foreign policy [and] strengthen and reform international institutions."

Hilary Benn, the international development secretary, said the special relationship had stood Britain in good stead, but warned: "I don't support the US position on the International Criminal Court, abstinence as a way of fighting HIV in Africa, Guantánamo Bay, or climate change."

Harriet Harman, justice minister, added: "We need to draw the US closer to our politics, rather than embracing theirs. Bush's failure to plan for recovery and reconstruction in Iraq was a huge mistake which has only increased the threat of international terrorism."

Only Hazel Blears, the Labour party chairwoman and ultra-loyalist, offered an uncritical defence of transatlantic relations. All the other candidates acknowledged the importance of the relationship but stressed the need to be a "critical friend". Alan Johnson, education secretary, said: "The last few years have been testing for the transatlantic relationship, but ... it will always be about more than the temporary passage of presidents."

At least five names will be on the ballot paper when nominations close on Thursday. Ms Blears, Mr Hain and Ms Harman, have all published lists of the 44 or more MPs nominating them, while Mr Johnson and Jon Cruddas, MP for Dagenham, are known to have passed the threshold but have yet to announce their backers.

But Mr Benn yesterday acknowledged that he had yet to sign up the necessary names and was beset by fresh difficulties after it emerged that he held shares worth £233,000 in a company which works for his department. Mr Benn said he declared the shares to the permanent secretary, Suma Chakrabarti, when he became minister and that there was no conflict of interest.