The Conservative Party will not return the whip to Julian Knight due to “further complaints”, after police dropped an investigation into a serious sexual assault allegation against the MP.

The Metropolitan Police confirmed their probe is over after Mr Knight said he had been cleared.

Mr Knight, who was suspended from the Conservative Party over the claim, always denied the allegation and on Wednesday demanded the “immediate” return of the party whip.

But a spokeswoman for Chief Whip Simon Hart said: “Following further complaints made to the Whips’ Office, we will not be restoring the Whip to Julian Knight.

“These complaints, if appropriate, will be referred to the relevant police force, or appropriate bodies.”

In a strongly worded statement on Wednesday, Mr Knight had hit out at both the Metropolitan Police and the response of his own party, promising to “use every legal route available to pursue those inside and outside Parliament” involved in the allegation.

“The fact is that there was never anything for the police to investigate,” the MP said.

“This was a single, false and malicious allegation initially brought to them by third parties, each of whom had their own clear motives for doing so.

“In publicly naming me in connection with the allegation, the Conservative Whips’ Office acted disgracefully and in breach of natural justice by removing my anonymity. Their actions meant my name was dragged through the mud and my good reputation immeasurably damaged.

“The conduct of one person in the Whips’ Office, and the language used towards me, was particularly egregious.

“Had the police taken the simple step at the outset of interviewing me under caution, they would have seen that the allegation was false and scandalous. Instead, they waited four months, without ever talking to me, before deciding there was nothing for them to investigate.

“I have been left effectively to prove my innocence through my public statements and letters to the commissioner of the Metropolitan Police and the Chief Whip. That cannot be right.

“It is now my intention to use every legal route available to pursue those inside and outside Parliament involved in having this allegation brought against me.”

Scotland Yard received an allegation of serious sexual assault last October 28, and on December 7 a further referral relating to the incident was made and an investigation into Mr Knight was launched.

On Tuesday the force said: “Police are no longer proceeding with an investigation. There have been no arrests.”

The Solihull MP, who has represented the constituency since 2015, is chairman of the Commons Digital, Culture, Media and Sport Committee.

Former cabinet minister Damian Green is currently acting chairman.

Mr Knight last month complained to Met Commissioner Sir Mark Rowley about the handling of the allegation, saying the investigation was “flawed and fundamentally unjust”.

He has been contacted for comment.