Alan Craig, leader of the opposition on Newham Council, has led the campaign against the mosque that the ultraorthodox Tablighi Jamaat wants to build on an 18-acre site half a mile from the 2012 London Olympic stadium.

He is urging the Mayor of Newham, Sir Robin Wales, to take enforcement action against the group for its unlawful use of the site in West Ham since October 2006.

"For two long years Newham Council have allowed Tablighi Jamaat to use the site without any planning permission at all," said Mr Craig who leads the Christian Peoples Alliance group on the Council.

"Why should this narrow separatist sect be allowed to flout the law like this, when the Council claims it promotes an active law and order agenda especially over anti-social behaviour, street safety and all other areas of borough life?"

Tablighi Jamaat has come under the close observation of intelligence services in recent years over suspected links to terrorism, despite the group’s insistence that it does not preach violence.

This week it emerged that the leader of the airline plot terrorist cell regularly attended a Tablighi Jamaat-controlled mosque in Walthamstow, northeast London.

"This looks like unacceptable favouritism by the Labour-run council towards this hostile and irresponsible group," said Mr Craig. "This is unacceptable, especially in the light of Tablighi Jamaat's clear links to other unlawful activities like Islamic terrorism."

Mr Craig has submitted a question for consideration at Newham Council’s meeting on Monday in which he asks whether the Mayor will take enforcement action against Tablighi Jamaat “in order to demonstrate that the Council expects all organisations and residents in the borough to act within and respect the law”.