The publicity from Mr Cameron's last prison visit was eemed "incredibly unhelpful" by a top civil servant and Jack Straw's Ministry of Justice, was reluctant to allow further visits.

In an email the civil servant said: "Last time Cameron visited a prison (supposedly without press) the photos ran in The Sun in an incredibly unhelpful fashion."

However, the email ended up being sent to Mr Cameron's private office by mistake.

A Conservative spokesman said: "This is a petty response by one of Jack Straw's officials, simply because The Sun decided to report about the problems in our jails. They are giving the impression they have something to hide."

The Ministry of Justice spokesman has agreed in principle to a visit.

On Thursday morning Mr Cameron met with young people at Morecambe's 'one-stop youth information centre'. And their verdict on the man many think will be the next Prime Minister was "he's really chilled out!"

Mr Cameron arrived in Morecambe at 9am on Thursday and spent over an hour talking to staff and users of the Information Centre for Young People on Kensington Road – a multi-agency centre that helps young people with all kinds of issues in their lives.

He discussed issues such as drugs, homelessness, education and sexual health and vowed to return to Morecambe in future.

"I came to see the Information Centre because it is quite an inventive project. I had heard how it brings together all agencies into one place and wanted to see it for myself," Mr Cameron told The Visitor.

"As Arnold Schwarzenegger might say, I will be back!"

Mr Cameron's visit was part of a tour of marginal constituencies in the North West.

Later the Tory leader went to Lancaster Town Hall and spoke to local estate agents about the current property market.

He was accompanied in Morecambe by David Morris, Conservative Parliamentary candidate for Morecambe and Lunesdale.