Macca & Mills: The seal pup tour

Sir Paul McCartney and his wife Heather Mills-McCartney were involved in a television row with a senior Canadian politician about the country's "brutal" commercial seal hunt.

The McCartneys frequently interrupted Newfoundland's Premier Danny Williams during CNN's Larry King Live, after Sir Paul had highlighted the issue of seal-clubbing with a high-profile visit to the ice floes of Canada hours earlier.

But the former Beatle and his wife were accused by Mr Willams of being "used" as they lent their names to the campaign to stop the killing.

The McCartneys took to the ice on Thursday in temperatures of -30C to see the seal pups at close quarters after being helicoptered to the Gulf of St Lawrence. The pair crept up to a seal watched by film crews to grab the world to attention before the hunting season starts in a few weeks' time.

They also called on the Canadian government to end the cull which claims the lives of 300,000 seals, earning £8.3m for the local hunters who sell the pelts from their prey.

Of his encounter with the seals, Sir Paul said: "It's a beautiful spectacle and it's the kind of thing that people should just respect and love. But it was terrifying to think that in probably about three weeks, sealers will arrive, and with clubs and with pickaxes and with guns to kill a huge amount of these baby seals."

The musician said the argument that it was a long-standing tradition did not wash. "We believe that 500 years is no justification for cruelty."

Appearing on the programme from Prince Edward Island, Sir Paul and Lady McCartney argued that ending the hunt could bring further economic benefits by developing the tourism industry. The Canadian government has denied the hunt is inhumane and has argued it is an economic necessity for the sealers, most of them from Newfoundland.

Mr Williams said the couple did not fully understand the issues and were being "used" by animal rights campaigners who organised the trip. Their visit was arranged by the British animal rights group Respect for Animals and the Humane Society International.

During the programme, Lady McCartney had to be told to let Mr Williams finish speaking after she accused him of talking "rubbish". Mr Williams, a millionaire lawyer before he turned to politics, said the couple's concerns could be levelled at numerous other industries.

"If you take the McCartneys' arguments to the extreme that they're willing to go, there will be no beef slaughter; there will be no pork slaughter; there will be no chicken slaughter; there will no fish in restaurants; there will be no eggs; there will be no milk for children in school milk programmes," he said.

Lady McCartney butted in. "Don't try to divert it. Rubbish. People eat meat; people eat fish; people don't eat the seals and they use it for fashion. It's not relevant."

In 2003, Canada approved a cull of nearly a million seals, from a population of 5.9 million, almost three times the number in the 1970s.