Some shopkeepers have seen their turnover drop by two thirds on this time last year and they think the poorly-timed roadworks and convoys are to blame.

Now Simon Hart MP is trying to help them get the message out that the town is very much open for shoppers – and that six new shops have opened since last year.

"It's been a very frustrating time for the traders who have already survived a tough twelve months," said Mr Hart.

"Main Street has been closed three times at peak trading times for wide loads bound for the new power station and there's at least another five convoys yet to pass through."

Trudi Lisle from Dragon Alley said: "It's absolutely ridiculous that these loads are being sent through on Thursdays which is one of the busiest days in town."

"The last time it happened we might as well have shut up shop and even after the lorry had gone through it was like a ghost town as everyone had been told to avoid Pembroke."

The next convoy is scheduled to pass through on the opening day of Pembroke Festival.

Mr Hart is now lobbying for them to be taken through the town at quieter times.

"With such long daylight hours at the moment surely they could come after trading hours or even on Sundays" he said.

The other problem is roadworks at the East End roundabout, one of the main entrances to town.

"There is a sign saying "businesses open as usual" but it's right by the roadworks, not 200 yards back where people might be stuck in traffic and making their mind up about whether to come to town," said Ms Lisle.

Pettina Sokell of the Mug Tree gift shop said: "Even last year in the middle of the recession I took more in February than I did in May this year after these roadworks and convoys started.

"It's going right through our peak trading season."