The Labour Party broke planning rules by using a shop as a campaign office.

Hove and Portslade's constituency party moved into premises in Portland Road, Hove, in April.

The building was used by the party's election candidate, Celia Barlow, and her team in the run-up to the General Election.

But managers failed to notice that planning regulations did not permit the building it was renting, a former shop, to be used as an office.

An attempt was made to change the use of the building retrospectively with an application for temporary planning permission. But the process took so long, the party had left before a decision was made.

Ms Barlow moved with her staff to new premises in Knoll Business Centre in Old Shoreham Road, Hove.

The constituency Labour party remains without an office and hopes to find alternative premises in the new year.

A spokesman for Ms Barlow, now Labour MP for Hove and Portslade, said: "In the heat of the election, we moved into Portland Road and later discovered that we may have been in contravention of planning regulations.

"This was an honest mistake for which we apologise. When we realised, we attempted to obtain temporary planning permission, however this was not possible.

"We therefore moved to our new premises at the end of August which are located in Unit W11 of the Knoll Business Centre on Old Shoreham Road."

A spokeswoman for Brighton and Hove City Council, which is responsible for enforcing planning rules, said: "In this case, like many, the planning department decided it was not expedient to take any enforcement action as the breach was accompanied by a retrospective application for consent and subsequently granted in any event."