A British MP has warned Saudi Arabia risks stirring revolution unless it introduces reforms and allows greater freedom of expression.

Crispin Blunt, a Conservative MP and chair of a parliamentary panel on detained Saudi women activists, urged the Saudi government to recognise that a civil society “is a necessary part of a political system that is meant to be a consultative monarchy”.

“The alternative to a consultative monarchy is an absolute monarchy and down that route lies disaster and eventually revolution,” he wrote in an op-ed for The Independent.

Mr Blunt, who described himself as a “friend” of Saudi Arabia, is among a group of cross-party MPs calling for the Saudi government to allow access to women’s rights activists detained in the country, following allegations that the women have been subjected to torture and sexual assault in prison.

More than a dozen were imprisoned in a crackdown by authorities in May last year, just ahead of the country’s ban on women driving being lifted. Many of them were prominent in the campaign to remove the ban.

Some were later released without charge, but at least eight women and a number of male supporters of the movement remain in custody. Human rights groups have said at least three of the women have suffered torture and sexual assault in Dhahban Prison, where they are being held, and all have been denied access to lawyers.

Saudi Arabia has denied the allegations, saying: “These recent reports by Amnesty International and Human Rights Watch are baseless.”

The panel wrote an open letter to the Saudi government earlier this month requesting access to the women detainees. Now, Mr Blunt has written to the new Saudi foreign minister, Ibrahim Abdulaziz Al‐Assaf, to make the same request.

“I write to request that you reassess the role the Women Activist Detainees have played in Saudi Arabian civil society, one which accompanied the welcome step, in June 2018, of women being allowed to drive in Saudi Arabia,” he wrote in the letter dated 14 January.

“I would be grateful if you would give our request the consideration this crisis commands and assist in facilitating the panel’s visit to Saudi Arabia to independently assess the conditions of the Detainees,” he added.