Jeremy Corbyn’s ‘joyless’ approach to life and its role in the collapse of his first marriage are to be revealed in a bombshell new biography of the Labour leader.

A devastating expose by renowned investigative author Tom Bower, being serialised exclusively in tomorrow’s Mail on Sunday, covers every aspect of Corbyn’s professional and personal life - and will add to the political pressures mounting on him over anti-semitism and Brexit.

The disclosures in A Dangerous Hero: Corbyn’s Ruthless Plot for Power - the result of 18 months intensive research and countless interviews with those close to Labour’s leader – include the truth behind the ending of his relationship with Jane Chapman.

Disclosures in A Dangerous Hero: Corbyn’s Ruthless Plot for Power reveal the truth behind the ending of Jeremy Corbyn's relationship with his first wife Jane Chapman

Jane Chapman, pictured with Corbyn in 1974, told Tom Bower that the Labour leader thought she had walked out on a 'feminist kick' but really she left because life with him was so arid

Chapman told the author Corbyn thought she had walked out ‘on a feminist kick’.

But the reality was that she left because life with him was so arid.

‘He would sit on the floor in his greasy, unwashed army surplus store jacket, oblivious to his wife’s irritation,’ writes Bower.

‘They rarely went out together. Dinner invitations were refused. Chapman spent lonely evenings in their small flat with Mango the dog and Harold Wilson the cat as her only companions while Corbyn met political cronies’.

Chapman also found holidays with Corbyn a chore: in one case riding pillion on Corbyn’s bumpy bike in Eastern Europe, shunning proper beds and interesting restaurants in favour of ‘a small tent and cooking tins of beans on a single ring Calor gas stove’.

But The Mail on Sunday’s extracts from A Dangerous Hero reveal that Corbyn refused Chapman’s requests for ‘more than just a political life’.

Soon after the break-up of the marriage, Corbyn embarked on a year-long affair with Diane Abbott, pictured at the Labour party conference last year, who is now Shadow Home Secretary

Diane Abbott at the House of Commons in 1987. Alongside her is Bernie Grant, centre, the Labour MP for Tottenham, and Jeremy Corbyn, right

Jeremy Corbyn, centre, with Shadow Home Secretary, Diane Abbott, left, and Shadow Home Secretary John McDonnell, right, arrive at the Labour Party conference in Liverpool last year

She says: ‘Jeremy never thought there was anything wrong. He assumed that, because our politics were compatible, that amounted to a proper relationship.

'He didn’t acknowledge my emotional side. He doesn’t recognise a woman’s feelings.’

Chapman walked out on Corbyn just before Christmas 1979. As she packed her belongings, Corbyn told her that she should ‘read Simone de Beauvoir’.

But, not having read the book, he failed to understand the feminist author’s call for women as ‘the second sex’ to elevate themselves by being more than just defined by men.

Chapman says: ‘He thought I left him on a feminist kick. But it was because I wanted some fun. His lack of emotional awareness didn’t change. My emotional life as part of a relationship was forgotten’.

Labour Leader Jeremy Corbyn is now married to his third wife Laura Alvarez, pictured together

Soon after the break-up of the marriage, Corbyn embarked on a year-long affair with Diane Abbott, who is now his Shadow Home Secretary.

The closeness between Corbyn and Abbott has led to claims that she is ‘bombproof’ in the party, despite a series of political gaffes.

Bower writes in the Mail on Sunday extracts: ‘Nearly 20 years later, Corbyn invited Chapman for tea in the Commons.

‘You should lighten up,’ he advised her, convinced as usual that he had been in the right. If anyone lacked a sense of humour, thought Chapman, it was her joyless former husband’.