CHARISMATIC London mayor Boris Johnson was mobbed as he walked down Chippenham High Street today.

Shoppers out enjoying the sun grabbed the opportunity to photo bomb the media's pictures of Boris with blue balloons in tow.

He barely managed a couple of steps along the campaign trail before being stopped again for another selfie, and he took it all in his stride.

Mr Johnson, whose second term as Mayor of London comes to an end next year, is standing as an MP in the West London constituency of Uxbridge and was visiting Wiltshire to support fellow Conservative candidate Michelle Donelan.

He said the sky’s the limit for Miss Donelan, but he would not be drawn on who in the long-term was most likely to end up in Number 10 – her or him, saying only “In the long-term as JM Keynes said, ‘We’re all dead’."

He said: “What the Prime Minister has said is that he will serve until 2020; that’s a very long time, Michelle will be coming up the ranks, there’ll be people coming up all over the place, there’ll be good female candidates such as Michelle.”

Mr Johnson and Miss Donelan told the BBC that Mayor of Chippenham and Liberal Democrat John Scragg had told them he hoped Miss Donelan wins on May 7.

But Coun Scragg told the Gazette: “That’s not true, I didn’t say that, I just said good luck. I wish every candidate good luck.”

Mr Johnson said he was interested by the dynamism of the Wiltshire economy, with Melksham's dairy exporter Coombe Castle Combe sending "great quantities" of its Wiltshire clotted cream to China.

He said the Conservatives had a great track record of turning the economy around: "But what we want to see is the benefits of that recovery being felt by town centres like Chippenham and that business isn’t being dominated by out of town shopping centres, by supermarkets, but that small shops get a look in as well; that’s absolutely vital for places like Chippenham.”

Mr Johnson has had to deal with how to reduce London's traffic congestion, but the Swindon to London railway line has seen the greatest price hike for season tickets since privatisation, according to the TSSA rail union, and it now costs over £9,000 a year from Chippenham to the capital.

Mr Johnson said: “Conservatives are offering a freeze on rail fares for the next five years, so we are going to keep it at RPI (Retail Price Inflation) for five years and I hope that will help reduce the problem. The difficulty is that, you’ve got to invest in your service, you’ve got to invest in track and signalling and these things don’t come cheap unfortunately. But I think a five-year freeze on rail fares is something that is do-able and we’re going do it.”