The General Election will go ahead as planned on June 8, despite the second terror attack to hit Britain during the campaign period, Prime Minister Theresa May has said.

Speaking in Downing Street after chairing a meeting of the Government’s emergency Cobra committee, Mrs May confirmed that campaigning for the poll will resume on Monday.

National campaigning was suspended following the outrage by all major parties apart from Ukip, whose leader Paul Nuttall warned that stalling the democratic process could lead to more attacks.

The terror threat was not raised from its “severe” level at the Cobra meeting in response to Saturday night’s outrage, which saw seven killed and 48 injured as terrorists drove a van into pedestrians at London Bridge and then attacked passers-by with knives.

But Mrs May made clear she intends to take action on a range of levels in response to the recent spate of atrocities, also including the car and knife murders of four people at Westminster in March and the killing of 22 by suicide bomb at the Manchester Arena last month.

She signalled action to clamp down on hate preaching and the use of the internet to spread Islamist ideology, as well as measures to end tolerance of extremism and a review of the powers of police and security agencies.

Jail sentences for extremism-linked crime – including less serious offences – could be lengthened, said the Prime Minister.

“It is time to say ‘Enough is enough’,” said Mrs May. “Everybody needs to go about their lives as they normally would. Our society should continue to function in accordance with our values. But when it comes to taking on extremism and terrorism, things need to change.”

Mrs May said it was right for election campaigns to be suspended as a mark of respect to victims.

But she added: “Violence can never be allowed to disrupt the democratic process, so those campaigns will resume in full tomorrow and the General Election will go ahead as planned on Thursday.”

Downing Street
Flags are flown at half mast in Downing Street, London, following Saturday night’s terrorist incidents on London Bridge and around Borough Market (Andrew Matthews/PA)

The Union flag was flying at half mast over Downing Street as ministers and security chiefs gathered for the Cobra meeting, also attended by Home Secretary Amber Rudd, Foreign Secretary Boris Johnson, Defence Secretary Sir Michael Fallon, Health Secretary Jeremy Hunt, Transport Secretary Chris Grayling, Communities Secretary Sajid Javid and London Mayor Sadiq Khan, along with representatives of police and security and intelligence agencies.

Sunday’s halt in campaigning is the second time that the election has been disrupted by terror atrocities, following a three-day pause after the Manchester attack.

The Joint Terrorism Analysis Centre (JTAC) moved the terror threat up to critical following the Manchester Arena attack, triggering heightened security measures including the deployment of military personnel to support police under Operation Temperer.

The threat level was last weekend lowered to the second highest category of severe, meaning an attack was judged “highly likely”.

Political parties were quick to announce that they were putting their national campaigns on hold following the London Bridge attack.

Labour leader Jeremy Corbyn said: “The Labour Party will be suspending national campaigning until this evening, after consultations with other parties, as a mark of respect for those who have died and suffered injury.”

And Liberal Democrat leader Tim Farron said: “The election must go ahead as planned. It is right that we suspend our national campaigning for a short while out of respect for those affected by these tragic events, but local campaigning can and must continue. The remainder of this campaign must be a collective showing of defiance and pride in our democratic values.”

However, Mr Nuttall said: “The only guarantee that will come from our choosing to stall the democratic process again will be more attacks – it is what these cowards want us to do.

“For those of us seeking to serve the people of this country, it is our duty to drive the dialogue on how best to confront and defeat this brand of terrorism. That is what Ukip will be doing today and beyond. Therefore, I refuse to suspend campaigning because this is precisely what the extremists would want us to do.”

A Labour party source said that Mr Corbyn will give a speech in Carlisle on Sunday evening addressing the London attack and setting out his Labour’s values. The party has cancelled a rally and its campaign battle bus will not be on the road during the course of Sunday.

Meanwhile, shadow foreign secretary Emily Thornberry criticised the Prime Minister for announcing a four-point plan to tackle terrorism, despite an agreement between the parties to suspend national campaigning.

She told BBC Radio 4’s The World This Weekend: “I don’t think it’s right to get dragged into plans at this stage so soon after those attacks. I do think this is a matter of timing.”

Asked if the announcement strayed into party politics, she said: “I think that it is drawing us into a debate. I think that there is time enough for us to discuss this issues.”

“To come out onto the steps of 10 Downing Street, immediately in the aftermath of a terrible outrage like this, was not something that would be expected. I just simply regret the approach that she has taken.”

Brexit Secretary David Davis said he did not believe there was any legal means of delaying the election from its scheduled date while Parliament was not sitting.

“I’m not sure it can be legally done,” he told BBC interviewer Andrew Marr. “In order to do this, you’d have to have some change in the law and who’s going to do that?

“Parliament no longer exists. I’m not a Member of Parliament for the duration, as are none of the other people who were MPs.”