Sir Malcolm Rifkind is to dramatically quit as an MP at the general election after being caught up in a new "cash for access" scandal.
The Tory grandee referred himself to the parliamentary commissioner on standards and denied any wrong doing after he was alleged to offer his influence in exchange for money.
But the Conservative Party suspended the Kensington MP after a meeting with chief whip Michael Gove and launched a disciplinary inquiry.
The move followed an investigation by Channel 4's Dispatches and the Daily Telegraph filmed the former foreign secretary claiming he had could arrange "useful access" to British ambassadors and also said he was "self-employed", despite MPs earning at least £67,000 a year.
Rifkind, who also announced he is to step down as chair of the Intelligence and Security Committee, said he had received "tremendous" support from his constituency association and constituents since the allegations.
Rifkind not running at general election
But the 68-year-old explained he had decided not to run at the general election, which is now just 72 days away, because his constituency association would face "serious uncertainty".
"I am conscious, therefore, that Kensington Conservatives are faced with serious uncertainty until the end of March as to whether I will be able to be their candidate. If I could not they would have little time to choose a new candidate," Rifkind said.
"I am also aware that even if the committee reach a favourable conclusion as to these allegations the controversy will remain during what is certain to be a heated general election and, indeed, for many months thereafter until the parliamentary commissioner for standards has completed the necessary enquiry.
He added: "I had intended to seek one further term as MP for Kensington, before retiring from the House of Commons.
"I have concluded that to end the uncertainty it would be preferable, instead, to step down at the end of this parliament."
Rifkind stressed the decision was "entirely" person and that he had received no requests from his constituency association to stand aside.
"As regards the allegations of Channel 4 and the Daily Telegraph I find them contemptible and will not comment further at this time," he added.
"Although I will retire from parliament I shall continue my public and political life and am much looking forward to doing so over the years to come."
A Conservative Party spokesman told IBTimes UK: "Sir Malcolm has had a long career of distinguished service both to the Conservative Party and the country. We respect and support his decision to stand down."