Geoff Hoon tried to secure an MPs' ballot on Gordon Brown's leadership
Former Defence Secretary Geoff Hoon has announced he will stand down as an MP at the general election.
The Labour MP, who tried to organise a vote on Gordon Brown's leadership last month, also served as the party's chief whip and as transport secretary.
He had been facing calls for de-selection by his local party in Ashfield, Nottinghamshire.
But Mr Hoon said he had had "consistent support" from Labour members, despite making "difficult decisions".
The Cambridge-educated former lawyer and lecturer has been an MP since 1992 and was defence secretary when the UK went to war in Iraq in 2003.
Some Labour activists in Mr Hoon's constituency are said to be angry about a letter sent by him and former Health Secretary Patricia Hewitt to Labour MPs last month urging them to hold a secret ballot on Mr Brown's future.
'Right to be heard'
It said the party was "deeply divided over the question of the leadership", but no current ministers supported their move.
Mr Hoon said as recently as last month that he would be Ashfield's Labour candidate at the next election, which is expected to take place on 6 May.
In his resignation letter, he said it had been a "great privilege" to be an MP and that he was "proud of what I have been able to achieve".
Mr Hoon also said: "Despite my involvement in difficult and sometimes controversial questions I have received consistent support from the people of Ashfield.
"They have recognised that it is necessary to take difficult decisions, that newspapers do not always report fairly or accurately and that I always tried to take decisions in the best interests of the country.
"I have had many Ashfield people say to me that they might not agree with my political views or my decisions but that they supported my right to be heard.
"I joined the Labour Party because I believed in equality, in freedom of speech and in tolerance, compassion and understanding for people, irrespective of their background and views. In whatever I decide to do in the future I will hold to those principles."
Mr Hoon left the cabinet last summer in a reshuffle triggered by the resignation of several ministers.