Beefy will walk for the hospital campaign

But Swansea-born Zeta Jones, 32, will not trek the entirety of Botham's latest, 229-mile challenge in April.

Instead, the America's Sweethearts star will join the stretch from Cardiff Bay to the castle in the centre of the capital, along with thousands of other walkers.

Botham's contribution is his Wales-wide walk is split in to nine legs.

"It's great to have Catherine, one of our two patrons, joining us in Cardiff and we all look forward to meeting her," he said.

"We are expecting thousands of walkers to join us on the Lord Mayor's Walk from the Oval Basin in Cardiff Bay, where family entertainment will follow the official end of the walk."

Parents want a hospital specially for children

The actress, mother of 19-month-old son, Dylan, returned the compliment in a statement: "Ian Botham's contribution to the success of the Noah's Ark Appeal has been immense.

"I am thrilled to be able to play a small part in celebrating the completion of his trek across Wales which has been so well supported by so many people across the country."

Following the walk, Zeta Jones is expected to attend a gala fundraising dinner at Sophia Gardens, hosted by Cardiff Lord Mayor Russell Goodway.

Singer and charity patron Charlotte Church is also on board for the event and will perform at the 27 April dinner.

Children's charity

She has supported the Noah's Ark Appeal since it launched in 2000 with the aim of raising �5m to build the first phase of a �21m paediatric care unit in the capital.

Cardiff and Vale NHS Trust has already provided the site and infrastructure and the Welsh Assembly has pledged an extra �4.5m on completion of phase one.

Relatives of some young patients have claimed paediatric facilities at the University of Wales Hospital in Cardiff are insufficient.

They kick-started the campaign to create a dedicated, 50-bed centre with two wards and a child-friendly warmth.

Wales is the only European country not to have such a hospital dedicated to treating sick children.