London (CNN) British lawmakers have called for Syrian President Bashar al-Assad's UK-born wife to stop backing his "murderous" regime or have her citizenship stripped.

Nadhim Zahawi, a member of the ruling Conservative party, told CNN that London-born Asma Assad , who has dual UK-Syrian citizenship, "has been using her social media platform in support of this murderous regime.

"Her husband has clearly crossed the line in terms of using poison gas on his own people and she has to make her mind up," said Zahawi.

A post shared by The First Lady Asma al Assad (@asmaalassad) on Mar 31, 2017 at 2:09am PDT

The member of Parliament, who was born in Baghdad to Kurdish parents, immigrated to the UK when he was a child. He sits on the foreign affairs committee.

'He's a monster'

The UK and US have blamed the Syrian president for a chemical attack that struck the rebel-held town of Khan Sheikhoun in Idlib province on April 4, killing 89 people, including children. Syria has vehemently denied the accusations.

Zahawi said of Assad: "He's made himself a monster and I think it's time we go after Assad and all his network of propagandists. Mrs. Assad, being a dual citizen, is a propagandist of this murderous regime."

CNN has reached out to an adviser to President Assad for comment and will update this story if we receive a response.

Asma Assad, 41, has an Instagram account, where pictures of her and her husband are posted with the hashtag #WeLoveYouBashar.

She also posts on Facebook and the Telegram encrypted messaging app, with more than 500,000 followers across her channels.

She has recently posted pictures of herself hugging children and holding hands with an elderly resident of Aleppo along with words of praise for her husband's regime.

Call for Home Secretary to act

Zahawi said the Home Secretary, Amber Rudd, has the power to strip British citizenship from dual nationals.

Tom Brake, a Liberal Democrat member of Parliament, has written to Rudd, calling for her to do just that in the case of Asma Assad.

"If Asma continues defending the Assad regime's murderous actions, the onus will be on the UK Government to deprive her of her citizenship or demonstrate that her actions are not seriously prejudicial to the vital interests of the United Kingdom," wrote Brake.

A Home Office spokeswoman told CNN: "The government takes its duty to protect the British public exceptionally seriously. We cannot discuss individual cases but the Home Secretary can deprive individuals of their citizenship where it is conducive to the public good to do so."

Home Office figures showed that 37 individuals were stripped of their citizenship between January 2013 and December 2014 under section 40 of the British Nationality Act 1981.

The grounds were either because the Secretary of State was satisfied that this was conducive to the public good or because the person had fraudulently obtained British citizenship.