Internet companies could simply move their money abroad if the Government introduces a potential terror tax to crackdown on the spread of extremist material online, critics fear.

Keith Simpson, a senior Tory MP and member of the Intelligence and Security Committee of Parliament, said taxing companies if they fail to cooperate with efforts to fight terrorism was an “attention grabber headline” but would be difficult to enforce.

Ben Wallace, the Security Minister, said "patience is running out fast" with web companies.

He accused them of putting profit before public safety and that “if they continue to be less than co-operative, we should look at things like tax as a way of incentivising them or compensating for their inaction”.

He also suggested web companies were “ruthless profiteers” - a remark which prompted an angry response from Facebook with the internet giant saying he was “wrong to say that we put profit before safety”.

Any levy could be similar to the windfall tax imposed on excess profits of privatised utilities by the Blair government in 1997, or the charge Margaret Thatcher's government placed on banks in 1981.

The amount of tax paid in the UK by internet companies relative to their overall profits has provoked widespread fury in recent months and has prompted questions about how effective any new charge would be.