Washington  - With only 14 days to go before the US general election, presidential candidates John McCain and Barack Obama crisscrossed swing states Tuesday that will be crucial to success on November 4.

Obama held a roundtable discussion in Tampa, Florida with economic advisors and state governors from across the country, part of a major tour this week by the Democratic nominee and his surrogates across the state that gave President George W Bush a wafer-thin victory in 2000.

Republican nominee McCain planned three rallies Tuesday across Pennsylvania and will head to Ohio along with running mate Sarah Palin on Wednesday. Ohio narrowly handed Bush his re-election in 2004. Pennsylvania went to Democrats in the last two elections, but the heavily populated state is still considered up for grabs.

The criss-crossing campaigns come as early voting began this week in a select few states including Florida, Nevada and Texas, prompting long lines of eager voters outside polling stations.

Record turnout is expected this election amid high passions, new registrations of young voters and an expansion of early voting opportunities. Officials expect more than 30 per cent of voters to cast their ballots before November 4.

McCain is fighting an uphill battle in the final two weeks as polls have given Obama a steady lead both nationally and in many of the swing states that will decide who takes over the White House.

But the race took a turn Monday night as Obama campaign officials announced their candidate would take a break from the trail for two days later this week for a previously unplanned visit to his ailing grandmother in Hawaii.

Obama will continue his scheduled events through Thursday afternoon, when he will fly to Hawaii to visit Madelyn Dunham, 85.

Obama, 47, a US senator from Illinois, was partly raised by his maternal grandmother. He has spoken often during the campaign of her influence on him and his respect for the sacrifices that his mother and grandparents made for him.

In Florida, Obama communications director Robert Gibbs said that the candidate will scuttle political events in Iowa and Wisconsin to visit Dunham, who has been ill and suffered deteriorating health in recent weeks. Obama plans to resume campaigning on Saturday. (dpa)