Sir Keir Starmer was warned not to turn Britain into an 'oppressive police state' after Labour pledged to review laws governing online posts in light of violent demos that spread across the country.
Shadow Home Secretary James Cleverly said he was 'uncomfortable' with calls to strengthen the Online Safety Act in light of misleading and hateful social media posts stirring up the riots.
The Prime Minister had earlier said that the online world was 'not a law-free zone' and that ministers would 'have to look more broadly' at cracking down harder following a number of arrests for riot-inciting posts yesterday.
But some parts of the legislation - including plans to compel platforms to take action on illegal content - will only come in next Spring, prompting accusations that the government will use the disorder to impose a more 'draconian' version of the law before the original is fully implemented.
It comes as Labour is also considering whether to adopt a definition of Islamophobia consistently rejected by the previous Torygovernment due to concerns over it stifling free speech.
Prime Minister Sir Keir Starmer has said the online world is not 'a law-free zone' as he pledged to review legislation around social media
Shadow Home Secretary James Cleverly said he was 'uncomfortable' with a tightening on free speech and urged the Government not to 'turn into an oppressive police state'
Mr Cleverly, who was in government when the Online Safety Act was passed, told Times Radio: 'It was carefully thought through when we brought it in.
'It struck the appropriate balance between managing misinformation, disinformation, propaganda, and what we have seen, which is incitement.
'I am uncomfortable with some of the calls that I've heard more recently... where people would fear that debate, legitimate debate, and disagreement becomes policed, and that we have some kind of social censorship by the backdoor.
'We also have to be very, very careful that we don't turn into an oppressive police state.
'The Labour Party has a long tradition of overreach in terms of freedom of speech and civil liberties and I don't want to see that happening again.'
The act became law last October and gives Ofcom the power to fine social media companies up to £18million, or 10 per cent of their global turnover, if they fail to take robust action against content inciting violence or terrorism.
It was also reported that the government could revive a provision to regulate 'legal but hamful' content taken out by the previous Tory government in order to give authorities more power to force firms to curb harmful posts.
Cabinet Minister Nick Thomas-Symonds said yesterday: 'If we need to act in relation to online safety laws - we will.'
Campaigners who have long warned about the importance of striking the right balance between tackling dangerous misinformation and censorship said strengthening the Act was 'reactionary and premature'.
Matthew Lesh, IEA director of Public Policy and Communications, said: 'The Online Safety Act will not actually come into force until later this year.
'So it's bizarre that the Prime Minister is already talking about strengthening provisions.
'You would think they would at least give it some time to figure out whether it works or not.
The Government has been accused of using the disorder to impose a more 'draconian' version of the Online Safety Act before the original is fully implemented next Spring
'Politicians love an easy scapegoat when things go wrong, and censoring the public rather than dealing with the true causes of rioting is the easy way out.
'There are already plenty of existing laws that can be used against people who stir up hatred and violence, these should be enforced before seeking more online censorship.'
Mark Johnson, of civil liberties group Big Brother Watch, added: 'Times of crisis often breed authoritarian responses, but this should be a moment for cool heads.
'The response to the riots which have taken place up and down the country this week should be one which protects human rights not erodes them further.'
Separately, ministers are weighing up whether to introduce an agreed description of anti-Muslim prejudice which was previously rejected over concerns around freedom of speech and feared blasphemy laws.
The party backed a definition drawn up by the All-Party Parliamentary Group on British Muslims while in opposition, with the Liberal Democrats and Scottish Conservatives also backing it.
But the previous government never actioned the proposal as they said it could have 'severe consequences for freedom of speech' when it came to criticising Islam.
The definition states: 'Islamophobia is rooted in racism and is a type of racism that targets expressions of Muslimness or perceived Muslimness.'
This week the Prime Minister was told by a senior Labour MP that adopting the wording could send a powerful message in light of far-right violence and rioting targeting Muslims across the country.
And Liberal Democrat leader Ed Davey told the Muslim News last night: 'The Prime Minister has an opportunity to take the swift, decisive action that the British Muslim community deserves.'
But in February, Kemi Badenoch, the shadow communities secretary, said the term 'anti-Muslim hatred' was more appropriate to both religious freedom and the freedom to criticise religion.
Responding to the wording accepted by Labour, Mrs Badenoch added: 'The definition of 'Islamophobia' [they use] creates a blasphemy law via the back door if adopted.'
