US:JOHN McCAIN is expected to appear with his running mate at a rally in the swing state of Ohio today as the Republicans try to halt any momentum gained by Barack Obama from the Democratic convention.
The Republican presidential candidate is hoping that the announcement will seize attention from Mr Obama's acceptance speech in Denver and build excitement ahead of his party's convention in Minnesota next week.
Mr McCain's choice remained a tightly guarded secret yesterday, but most speculation focused on two long-term favourites: Mitt Romney, the former governor of Massachusetts, and Tim Pawlenty, governor of Minnesota.
Joe Lieberman, the former Democrat turned independent senator for Connecticut, was also thought to be under consideration, despite warnings from conservatives that his support for abortion rights would split the party.
Mr McCain's decision appeared to boil down to a choice between solidifying the Republican base with a solidly conservative pick such as Mr Romney or Mr Pawlenty, or reaching out to independents and Democrats with Mr Lieberman.
A Washington Post poll this week found that 20 per cent of McCain supporters would be less likely to vote Republican if he selected a running mate who favoured abortion rights. Conservative leaders warned such a choice would create deeper divisions among Republicans than those between the Obama and Clinton camps of the Democratic party.
Many analysts thought it highly unlikely that Mr McCain would jeopardise his progress in unifying the Republican party since sealing its presidential nomination.
Mr Pawlenty would be viewed as a safe choice because of his conservative record on social and fiscal issues - and he could help the Republicans carry Minnesota, one of the party's top target states. But he is little-known among ordinary voters outside his home state.
Mr Romney would be a riskier choice because his Mormon faith alarms some evangelical Christians and he faced charges of flip-flopping during the primaries because of his inconsistent record on social issues. He eventually won over many conservatives and emerged as the strongest challenger to Mr McCain.
The two men showed little affection for each other during the campaign, but Mr Romney has since become one of Mr McCain's most effective advocates. His business background could help offset Mr McCain's weakness on economic issues in a year when the economy is the top voter concern.
As a Michigan native, Mr Romney could also carry a crucial midwest battleground. Nonetheless, his ties to the private equity industry and his wealth of up to $250m (€170m) would make him an attractive target for Democrats.
The Obama campaign recently made Mr McCain's wealth - stemming from his wife's status as heiress to a large beer business - an issue when he seemed to forget how many homes he owned.
As a national security hawk who broke from the Democratic party over the Iraq war, Mr Lieberman would reinforce Mr McCain's foreign policy strengths and match the experience brought to the Democratic ticket by Joe Biden, one of the leading Senate experts on international affairs. Mr Lieberman was Al Gore's running mate for the Democrats in 2000.
Other contenders recently linked with the job include Tom Ridge, former governor of Pennsylvania, and Kay Bailey Hutchinson, senator for Texas. - (Financial Times service)