Brexit news: Tory leadership candidates brace for screenings of TV interviews as time runs out for votes to be cast

A petition to reverse Brexit and stay in the EU is the biggest in British history, according to parliamentary authorities.

The campaign, which received 6.1 million signatures, was known to be the biggest online UK petition but has now been confirmed to be the largest of all time.

According to the House of Commons library, it beats a 1945 petition by the British Federation of Old Age Pensioners, which asked for new laws to help pensioners. That was signed by "approximately" 6 million people.

The UK is set to miss its climate change targets because of the government's "failing" policy on energy efficiency, a committee of MPs has warned 

Suspending parliament to force through a no-deal Brexit would trigger a "constitutional crisis", Philip Hammond has said. 

The chancellor said he supported former prime minister Sir John Major's threat to take legal action if the next prime minister tried to suspend parliament to push through no deal.

Mr Hammond told Bloomberg: 

"If anybody were to attempt to shut down parliament in order to carry out a course of action which parliament is known to oppose, that would be very serious indeed.

"That would provoke a constitutional crisis.

"And, if we aren't able to prevent that course of action through parliament, then, certainly, there will be resort to the courts, and I strongly support the position that Sir John Major has taken."

Jeremy Hunt has refused to say that his rival, Boris Johnson, is not to blame for the resignation of the UK's ambassador to the US, Sir Kim Darroch, earlier this week. Mr Johnson had refused to back the embattled ambassador, who was at the centre of a row over leaked criticism about Donald Trump's government.

The foreign secretary also claimed the UK wants to "de-escalate the situation'' in the Gulf, following reports of a confrontation between a British warship and Iranian Revolutionary Guard boats.

Mr Hunt told BBC Radio 4's World At One programme: "We have a responsibility to protect British shipping and with our allies to protect the waterways and seaways of the world so we have to react according to the threats that we face.

"But this is not an Iran-specific issue - notwithstanding the broader tensions in the region - this is about Syria and about a breach of the sanctions against Syria which of course is a country that Iran is active in."

He said sending HMS Duncan and having HMS Montrose in the region was "about our responsibility to do everything we can to protect British shipping".

Mr Hunt added: "We consider this a serious situation but the prosperity and peace that we have enjoyed for the last 75 years has been because basic international norms have been followed, including not using chemical weapons which is what has been happening in Syria."

During his radio interview, Irish prime minister Leo Varadkar also talked about border checks in the event of a no-deal Brexit.

He suggested Northern Ireland should stay in the same food and animal standards zone as the EU - which would mean an SPS (sanitary and phytosanitary) border between Britain and Northern Ireland.

"The kind of things that we're looking at and proposing, for example, is that the entire island of Ireland will be treated the same when it comes to agriculture or food and that any SPS checks would happen at the ports," Varadkar told Newstalk.

"That would mean Britain accepting that Northern Ireland is being treated differently. The other things obviously are checks at business level and random checks and controls, and we'll have to have a lot more of them anyway because of smuggling."

A new attempt to stop the next prime minister suspending parliament to force through a no-deal Brexit has been launched in the House of Lords, reports political editor Andrew Woodcock.

Peers are proposing an amendment to force Theresa May's successor to provide MPs with an opportunity to vote in the days leading up to 31 October.

Tory peer Lord Ashcroft, previously a major donor to the party and its deputy chairman, has backed Jeremy Hunt to be the next prime minister 

The March for Change group has launched a crowdfunder to make a 7-metre high inflatable effigy Boris Johnson for use at its "No to Boris. Yes to Europe" demonstration on 20 July.

The blimp will have Mr Johnson's promise that the NHS will receive an extra £350m a week after Brexit printed on it.  

The group said it would fly 20 metres above Parliament Square, "symbolising [Mr] Johnson’s hot air over Brexit".

Tom Brufatto, Chair of Britain for Europe, said: 

“Boris Johnson is about to float into the most powerful position in the land, based on nothing more than his over-inflated ego and the votes of just 0.2 per cent of the population. 

“The Boris Blimp might seem just lighthearted fun but it carries a serious message. Inspired by Trump Baby, we want to welcome our next prime minister with the same grassroots spirit of protest. With mutual friends like Steve Bannon and Nigel Farage, there is no doubt Johnson is just as dangerous and divisive as his pal Donald.

“We’d urge everyone who’s disgusted by Boris Johnson’s views on women, ethnic minorities, the LGBTQ+ communities, and tax cuts for the rich, to demonstrate with us on 20 July and if they can, to chip into our crowdfunder so the Boris Blimp can join us too.”

Brexit has sent "not as important" Britain into decades of decline, Irish premier Leo Varadkar has said