Mr Duncan Smith met fishing representatives in Looe

He told them the Conservatives will place the industry under national control if they win the next general election.

His day-long visit to the Duchy also included a trip to the Eden Project, near St Austell.

He arrived in Looe on Thursday morning, as a full parliamentary investigation into the employment of his wife in his private office begins.

That inquiry is under way and I am utterly confident it will clear my name Iain Duncan Smith Tory Leader swaps hot houses

It follows claims by the investigative journalist Michael Crick that Betsy Duncan Smith did not do enough to justify her salary from public funds.

Along with the Conservative MEP Jonathan Evans, Mr Duncan Smith met fishermen and their representatives in Looe Harbour before heading off to visit the Eden Project.

During his visit he was also talking about new party policies, as well as the prospect of removing European power over the fishing industry and bringing it back under national control.

He pledged to take Britain out of the Common Fisheries Policy (CFP).

He said during his visit to Looe: "Some 60% of the value of the fish stocks of the European Union lie within British waters.

"I think it's fair that the British people should have some control over that."

However, some local members of the fishing industry said they were sceptical and said no government has ever truly supported them.

Willing party

Martin Thomas, who has been fishing since he was 11, said Westminster as a whole, not just the Tories, must help the industry.

He said: "Consistently, year on year, quotas are being cut.

"The fishing fleet has been halved in the last 10 years and we are losing the experience of people coming up and those skills will never be replaced."

But Looe fish merchant and former fisherman Tim Curtis, 36, said: "The industry has got to be taken out of the CFP in order for it to survive. We have got no control over our own waters.

"The Conservatives are the only party that is saying they are willing to do it, or saying it is possible to do it."

On his visit, Mr Duncan Smith refused to be drawn on details of the Parliamentary Standards Commissioner's inquiry.

He said: "I called for this inquiry. I wanted the inquiry. That inquiry is under way and I am utterly confident it will clear my name. That is all I want to say about it."