Ministers are considering strengthening security laws after a report by MPs accused them of underestimating the threat of Russian interference.
Transport Secretary Grant Shapps said a new law requiring foreign agents to register in the UK was being looked at.
He said the move would not be the “only solution” to security threats, but could make it easier to extradite spies.
Labour criticised “systemic failings” in the UK’s response to Russia.
Mr Shapps said the government was already taking a “more forward-leaning approach” but also thought the time was right for “additional powers”.
Speaking on Radio 4’s Today programme, Mr Shapps said registration “might be very useful”, although he cautioned it was “not the entire answer” to dealing with threats.
The government, which will have to answer questions on the issue in the Commons later, faces calls to do far more to counter Russian espionage and subversion after Parliament’s Intelligence and Security Committee (ISC) said the UK was the main target after the US and Nato.
In a 50-page report, the committee said the UK was “clearly a target” for disinformation campaigns around its elections, but that the issue was described as a “hot potato”, with no one organisation taking a lead to tackle it.
ISC member Kevan Jones told BBC Breakfast he hoped any government announcement about new legislation – which was one of the recommendations of the report – wasn’t “just spin” and actually resulted in action.
The law under consideration could mirror the new “Espionage Act” suggested by the committee, which would make it explicitly illegal to be a spy in the UK, BBC political correspondent Chris Mason reported.
Such an Act would compel those who represent the interests of foreign powers to register on arrival in the UK. Those who did not – and so operated covertly – would be breaking the law.
If you do not seek, you do not find.
Whether deliberate or deficient, the Intelligence and Security Committee’s very long-awaited report outlines gaping holes in the UK’s handling of the threat from Russia.
For years, it seems a lack of priority, and a lack of curiosity, allowed the risks to go unmonitored, if not to go unchecked.
The UK government has now stiffened its attitude to Putin’s Russia.
The MPs’ report claimed the government made no effort to investigate claims of Russian interference in the EU referendum and criticised intelligence agencies for not giving the issue more attention.
And it said the government only “belatedly realised the level of threat which Russia could pose” after the so-called “hack and leak” operation against the Democrats in the 2016 US election, calling it a “game changer”.
‘Tools and resources’
Labour will later use an Urgent Question in Parliament to highlight what it says are multiple “shortcomings” in the UK’s national security policy shown up by the report.
Shadow home secretary Nick Thomas-Symonds said the government had failed to offer the UK’s security services “the strategic support, the legislative tools or the resources necessary” to defend the country’s interests.
Mr Thomas-Symonds said Labour would support the government if it brought forward measures recommended in the report – such as new legislation and working with online companies to ensure they act “swiftly to deal with hostile state activity on their platforms”.
He told Radio 4’s Today that the report “draws extraordinarily stark conclusions about the failure of our government” and its significance must not be “underestimated”.
“There was no single minister, no single government department that was responsible for the protection of our democracy and our democratic discourse and that absolutely now has to change.”
The government has rejected the committee’s call for a full assessment by intelligence agencies of potential Russian meddling in the 2016 EU referendum, saying it had “seen no evidence of successful interference”.
Foreign Secretary Dominic Raab said on Tuesday: “We’ve been clear that Russia must desist from its attacks on the UK and our allies.
“We will be resolute in defending our country, our democracy and our values from such hostile state activity.”
Mr Raab “categorically rejected” claims by SNP MP Stewart Hosie, a member of the ISC, that the government “actively avoided” looking for evidence of Russian interference.
Downing Street was accused of holding back the report ahead of December’s UK election and for delaying its nominations to set up the new committee – both claims it has denied.
The Russian Foreign Ministry called the report “Russophobia”.
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