Jeremy Corbyn's Brexit speech - as it happened: Labour leader backs UK membership of a customs union after leaving EU

David Lidington, the Cabinet minister, is also expected to deliver a speech on Brexit later today, claiming it should not be used as an excuse to break up the UK.

The country is at a crossroads but severing ties would leave every one of the four nations "weaker and poorer", the PM's deputy will say.

In the latest of the Government's Road to Brexit speeches, Mr Lidington will call for the UK to pull together.

Speaking at Airbus in North Wales, the Cabinet Office Minister is expected to say: "We as a country are at a crossroads in our history. We face a choice: a choice that represents the difference between a prosperous, secure nation that is united at home and stronger abroad, and a poorer country that is divided at home and a weaker player on the global stage."

"We are all more prosperous and more secure when we all work together for our common good as one United Kingdom," he will add.

"Leaving the EU presents many challenges for our centuries-old union story - and opportunities too. Some want to use it as an excuse to loosen these ties that bind us together - even sever them completely.

Barry Gardiner, Labour's Shadow International Trade Secretary, has just been on Radio 4 speaking about Labour's Brexit policy shift. 

Gardiner, who has previously described remaining in a customs union agreement with the EU after Brexit as "deeply unattractive", was sent out to defend precisely that - before Jeremy Corbyn is officially expected to announce this as Labour's new policy. 

But asked about the single market, he added that it is not consistent with “respecting what the British people asked us to do”

“The British people voted against what is the project of ever closer union. The British people took a decision that we would leave the European Union

“They wanted us to make sure that we were regaining what they saw as our sovereignty – that we were not paying money into the budget of the European Union and that we had the ability to control our own borders

“All of those things are things that we would not be able to do if we were part of the European Economic Area and, therefore, of the single market”

In Parliament today, legislation is expected to be introduced to tackle rip off energy tariffs for 11 million British households. 

The Domestic Gas and Electricity (Tariff Cap) Bill would allow Ofgem to limit tariffs until 2020, with the option to extend the cap annually until 2023.

Theresa May said the Bill, which the Government hopes will become law before next winter, would "force energy companies to change their ways".

A 2016 report found consumers were paying £1.4 billion a year over the odds via energy companies' standard variable tariffs (SVTs).

Announcing the Bill, Mrs May said: "It's often older people or those on low incomes who are stuck on rip-off energy tariffs, so today we are introducing legislation to force energy companies to change their ways.

"Our energy price cap will cut bills for millions of families.

"This is another step we are taking to help people make ends meet as we build a country that works for everyone."