( BBC ) - All nine Republican candidates for the 2008 US presidential nomination are gathering for a televised debate in the industrial city of Dearborn, Michigan.
Michigan is the US state with the highest unemployment and the debate is expected to centre on the economy.
Nationally, the Republican front-runner is former New York Mayor Rudy Giuliani.
But attention is likely to focus on former Tennessee Senator Fred Thompson, who is joining a candidates' debate for the first time in this race.
Mr Thompson, better known to many people as an actor in the television series Law & Order, only joined the race for the nomination in September, several months after his rivals.
He was criticised for choosing to announce his candidacy on the Tonight Show with Jay Leno on the day that his competitors were taking part in a debate in New Hampshire.
Tuesday's debate will provide a platform for Mr Thompson and his rivals to address heavyweight economic issues.
With only three months to go before the start of the primary season, when state parties pick their preferred candidate to stand for president, the candidates will be keen to impress.
While Mr Giuliani leads in national polls, former Massachusetts governor Mitt Romney is ahead in the key early voting states of Iowa and New Hampshire.
Michigan, in the US Midwest, recently defied national party rules to move its primary up the calendar to 15 January, in an attempt to gain greater influence over the nominating process.
Dearborn is in the heartland of manufacturing America and people will want to know how all the candidates would boost the incomes of working Americans and protect US manufacturing jobs, says the BBC's Vincent Dowd in Washington.