Is Jacob Rees-Mogg the most powerful man in Britain?

The Conservative MP has been called the “Honourable Member for the 18th century”, and some of his ideas do seem old-fashioned.

He’s got six children, but says he’s never changed a nappy because the family nanny does it instead.

He’s embraced Twitter but his first message to followers was in Latin, reading: “Tempora mutantur, et nos mutamur in illis”. It means: “the times change, and we change with them”.

And he once recited a 19th century poem in the House of Commons, somewhat to the annoyance of MPs who were trying to debate animal welfare.

But Mr Rees-Mogg is no joke.

He’s the chairman of a powerful group of Conservative MPs who are pushing for a “hard” Brexit.

They’re called the European Research Group. And they have the numbers to bring Prime Minister Theresa May down, either by defeating her in important House of Commons votes or by triggering a contest to elect a new Tory leader.

Yardley Labour MP Jess Phillips meets visits the North East Somerset constituency of Conservative Jacob Rees-Mogg for a Channel 4 News package
Yardley Labour MP Jess Phillips meets visits the North East Somerset constituency of Conservative Jacob Rees-Mogg for a Channel 4 News package

This is one of the reasons Mr Rees-Mogg, aged 48, has been such a visible figure recently, appearing on television to explain why the UK must leave the EU Customs Union or attacking Treasury civil servants for undermining Brexit.

The media have always been fascinated by Mr Rees-Mogg because he’s colourful and eccentric. But now, his words carry weight because Theresa May needs to take him seriously.

It’s unclear how many Conservative MPs are supporters of the European Research Group. A figure of 70 has been suggested, but this seems to include MPs who have simply been added to the group’s WhatsApp channel, a mobile phone messaging service.

The number of fully paid-up members - there is a fee - appears to be significantly smaller.

Anna Soubry, a pro-EU Conservative, claimed last week that the Conservative front bench “is in hock to 35 hard ideological Brexiteers.”

After the Tories lost their majority in last year’s election, 35 rebel MPs is more than enough to inflict defeat on the Government in the House of Commons.

It takes 48 to trigger a leadership contest but, given that other sections of the party are also uneasy, Mrs May can’t afford to alienate a co-ordinated group of 35 or so.

Not everyone agrees that the European Research Group is dictating policy. Some Conservative MPs point out that Theresa May is committed to proceeding with Brexit, and the group largely supports the policies she’s put forward since becoming Prime Minister.

But its profile and influence is growing - along with that of its unconventional chairman.