A US politician tipped as the next US President and known to favour state power to define gay marriage laws will address the Conservative Party Conference in Bournemouth next month, according to reports.

John McCain, senion Senator from Arizona, who voted against the Federal Marriage Amendment in 2004 and has been praised by gay lobby group the Log Cabin Republicans, will speak at the opening evening of the Tory annual gathering.

The coup is seen as a sign that the party and leader David Cameron are being seen as viable alternatives to Labour, according to The Times

Senator McCain is viewed as a leading candidate to stand as the Republican President in 2008. If elected he would be the oldest US President.

He has previously been critical of President George W Bush’s stance on gay marriage, but more recently has fallen in line with Republican policy as seen in his support of the more recent Federal Marriage Amendment, in what commentators describe as political pandering to cement his candidacy.

He was recently criticised for endorsing the actions of anti-gay activist Jerry Falwell after agreeing to keynote the spring graduation of Liberty University.

Other Republican candidates for nomination include former New York Mayor, Rudolph Giuliani, who recently drew criticism for supporting anti gay figures, and Mitt Romney, Governor of Massachusetts, a controversial figure in politics since publicly denouncing the legalisation of same-sex marriages in his state.