McCain/Lieberman '08?

Joe Lieberman, the former Democratic vice-presidential nominee who has endorsed John McCain, is being vetted as a potential running mate for the Republican presidential hopeful, according to an adviser to Mr McCain’s ­campaign.

Mr Lieberman, who has campaigned for the Arizona senator, has long been ­considered an unconventional but plausible choice for Mr McCain.

Although Democrats have rejected Mr McCain’s image as a maverick politician, Mr Lieberman’s support for the presumptive Republican nominee has, much to the chagrin of his former ­colleagues, helped to boost Mr McCain’s reputation as a bi-partisan legislator with friends on both sides of the aisle. Mr Lieberman, a staunch supporter of Israel, could also help Mr McCain win over Jewish voters.

“[McCain] loves Lieberman. And he is on the [short-]list because Lieberman has never embarrassed anyone, never misspoken. The first rule is, don’t take someone who costs you votes,” said one McCain adviser.