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.
Mr Simpson told The Telegraph: “Part of me says ‘well, good luck’ if you think that this can persuade them and raise money.
“I suspect that it will be incredibly difficult.”
He said companies could react to any attempt to impose a new levy by moving their money away from the UK.
“It is convenient to use the UK for many reasons but they might decide to go to another European country or somewhere else,” he said.
“It is incredibly difficult to do this but that is not to say that we shouldn’t try to do this.
“I did think this was a bit of an attention grabber headline.”
Mr Simpson said he believed the “broad mass of the public would agree” with such a windfall tax being introduced “but merely making promises is not enough”.
Mr Wallace said in an interview with the Sunday Times that obstruction and inaction by social media companies is costing taxpayers hundreds of millions of pounds as law enforcement agencies pick up the cost of tackling radicalisation.
Simon Milner, of Facebook, said: “Mr Wallace is wrong to say that we put profit before safety, especially in the fight against terrorism. We’ve invested millions of pounds in people and technology to identify and remove terrorist content.”
Meanwhile, a spokeswoman for YouTube said the video website is “doing more every day to tackle these issues” while Twitter said 95 per cent of terrorist content was removed proactively from the site.