After a strong finish in Iowa, Paul returns to New Hampshire to campaign against new party favourite Rick Santourum

Republican presidential candidate Ron Paul opened the battle for second place in the New Hampshire primary with an attack on his main rival, the rising star of the party right, Rick Santorum.

Paul, after a couple of days of holiday back in Texas after the Iowa caucuses, returned to the fray Friday, making Nashua his first campaign stop.

Demonstrating his drawing power, hundreds of supporters turned out in the unlikely and awkward setting of an aircraft hanger.

Such was demand to see him that cars quickly filled the parking spaces, and vehicles were left by the side of the highway, with lines running back at least a mile.

Paul, a maverick candidate on the libertarian wing of the Republican party, has a passionate, devoted, and largely young following. His arrival was greeted with chants of 'President Paul'.

Long on the fringes of American politics, he is enjoying a rare burst of popularity, a career high for the 76-year-old. His espousal of foreign non-intervention is in chime with the anti-war mood of many young people. It resonates especially in New Hampshire, with its long tradition of independent thinking.

Paul, who came a close third in Tuesday's Iowa caucuses, is running in second place in New Hampshire, well behind Mitt Romney. His main mission is to retain that second place finish by holding off Santorum, one of the surprises of Iowa, fighting Romney to a near dead-heat.

With Santorum rising in the polls in New Hampshire, Paul delegated his son Rand, the junior senator from Kentucky, a Republican and Tea Party favourite, to criticise Santorum.

Paul junior told the crowd that unlike his father, who voted against excessive spending by the federal government, another candidate with the initials 'RS' and who did well in Iowa, had repeatedly voted in support of foreign aid, the department of education and other spending programmes.

Paul senior stuck mainly to his stump speech, expressing opposition to the wars in Iraq and Afghanistan and any conflict with Iran. "Getting along with people is a lot better than dropping bombs on them," he said.

Polls indicate he has little chance of winning the Republican nomination but he has the money and organisation that will enable him to stay in the race, accumulating delegates to the party's convention in August. As delegates are distributed on a proportional basis, Paul is well-placed to gain a share of New Hampshire's 12.