British Prime Minister David Cameron has accepted an invitation to address a special session of the European Parliament on his planned referendum over Britain's membership in the 28-nation bloc, a leading MEP member says.

"I am delighted Cameron has, in principle, accepted my invitation to the European Parliament. This is a chance for him to finally put his cards on the table in a transparent manner," Liberal Group leader Guy Verhofstadt said.

Verhofstadt has, time and again, called for the British prime minister to explain his position on the planned referendum. Last week, MEP members unanimously agreed to invite Cameron and asked European Parliament President Martin Schulz to approach him.

Schulz's office said he had spoken to Cameron on Wednesday to discuss the issue.

There was no immediate official confirmation from London  but an EU press officer has been quoted as saying that "Cameron had a broadly favorable attitude towards the invitation”

Vote on Britain's EU membership was one of the promises of Cameron during the last elections which won with absolute majority. Cameron says he will campaign for a 'Yes' vote in the 2017 referendum only if he successfully re-negotiates with European leaders about Britain's membership terms.

Recent polls have shown a majority of Britons want to stay in the 28-nation bloc.