The Blue Anchor, which is owned by Greene King, was forced to close earlier this week due to the unwelcome visitors.
One diner, Gary Marsh told a local newspaper: “We were plagued with flies. It was disgusting. There were hundreds of flies everywhere and when our food arrived they were all in the food.
We were moved to a different part of the restaurant where they said it wasn’t as bad but it was just the same.”
Marsh added that his group was originally asked to pay the full bill but received a refund after they complained. Locals stressed that other places in the area had suffered from similar problems.
A spokesperson for the pub said: "The unexpected appearance of a number of flies earlier this week meant that for a short time, we were not able to serve our customers to our usual high standard, and we apologised unreservedly to those of our customers that this unprecedented and brief incident affected. We are still investigating but our specialist contractors can find no obvious cause for this strange occurrence. Thankfully things seem to be back to normal now and on the advice of Environmental Health officers, the pub re-opened for lunch yesterday and it is business as usual.”