Nadine Dorries referred to authorities over messages to officials

Nadine Dorries has been referred to the Conservative chief whip by the UK's top civil servant over claims she sent "forceful" messages to officials.

The Mid Bedfordshire MP announced she would be standing down as an MP just before former PM Boris Johnson's resignation honours list was unveiled.

Ms Dorries has accused Rishi Sunak's team of denying her a peerage.

Simon Case said he had flagged messages from Ms Dorries to the Commons Speaker and Tory chief whip.

Chief whips oversee discipline in political parties, while the Speaker presides over the House of Commons.

Tory MP and public administration committee chairman William Wragg, a frequent critic of Mr Johnson, asked Cabinet Secretary Mr Case if he was aware of "any rather forceful communications" sent by Ms Dorries "to senior civil servants".

Mr Wragg suggested Ms Dorries had threatened to use "the platform of the Commons and indeed her own television programme to get to the bottom of why she hadn't been given a peerage".

Mr Case said: "Yes, I was aware of those communications and have flagged them to both the chief whip and Speaker of the House."

Asked if he had taken legal advice on whether the Honours (Prevention of Abuses) Act 1925 could "come into play", Mr Case said he was "seeking further advice". The Act bans the sale of peerages or any other honours, such as knighthoods.

Ms Dorries initially announced she was standing down as an MP with "immediate effect", but later said she will not resign until she gets more information on why she was denied a peerage.

She has put in Subject Access Requests to get all correspondence between the House of Lords Appointments Commission (HOLAC), Cabinet Secretary and the Cabinet Office.

Subject Access Requests allow an individual to receive a copy of all their personal data held by a government department. The right of access to personal data does not apply to data processed for the honours system, under the Data Protection Act 2018.

While Ms Dorries remains a member of Parliament, she can turn up in the House of Commons chamber to make her views known.

The Conservatives - who are trailing Labour in national polls - are facing three by-elections before Parliament's summer recess.

But if Ms Dorries keeps her party waiting to resign and bring about a further by-election, she could force them into a potentially divisive contest later on - for example, ahead of the autumn party conference season.

The Liberal Democrats called on the prime minister to withdraw the Tory whip from Ms Dorries - meaning she would no longer be a Conservative MP - while the claims are investigated.

Daisy Cooper, the Lib Dem deputy leader, said: "These allegations are staggering and it's crucial a swift investigation takes place into whether Nadine Dorries may have broken the law."

It comes as it was confirmed that the Ms Dorries has written a book titled The Plot: The Political Assassination Of Boris Johnson. It will be published days before the Tory Party conference in September.