Michael Meacher, who has died aged 75, was a stalwart of the Labour left who served on the party's front bench for 29 years and was a minister for 11 despite being a passionate advocate of views which often put him at loggerheads with his own leaders.

An acolyte of left-wing darling Tony Benn, Mr Meacher launched a short-lived bid to challenge Gordon Brown for the leadership in 2007 and was one of 36 MPs who nominated the left-winger Jeremy Corbyn for his successful pitch for the top job after this year's election.

He was first elected to Parliament as MP for Oldham West in 1970 and served the constituency – whose boundaries were changed in 1997 to include Royton – for 45 years.

Appointed to a junior ministerial role within four years of his arrival at Westminster, he served Harold Wilson and James Callaghan in the industry, health and trade departments before becoming a fixture in the shadow cabinet through most of Labour's time in opposition.

He stood for the party's deputy leadership in 1983, but was well beaten by Roy Hattersley, coming in second with 28 per cent of the vote.

Although regularly re-elected to the shadow cabinet by the party's MPs in opposition, he was denied a Cabinet post by Tony Blair when Labour returned to power in 1997, and was instead appointed minister for the environment, a role he held until 2003.

One of his proudest achievements as environment minister was the introduction of the right to roam, which opened vast swathes of land in England and Wales to walkers.

He represented the UK at the Kyoto climate change talks in 1997 and was a strong supporter of measures to cut carbon emissions and tackle man-made global warming. He campaigned on renewable energy, organic agriculture and measures to mitigate the environmental impact of industry.

Mr Meacher took a lot of flak for his proposal in 1999 for a ban on second homes to prevent long-time residents being priced out of rural areas, after it was revealed that he and his wife owned a number of properties.

His increasingly "green" rhetoric – including attacks on genetically modified (GM) food – were an increasing cause of irritation to Mr Blair, and he was tipped as a candidate for the sack at each of the PM's reshuffles until he was finally removed in 2003. His survival until then was credited by some to his impressive technical grasp of complex environmental issues and to Mr Blair's preference to keep him occupied with government business rather than campaigning from the backbenches.

Mr Meacher voted in favour of the Iraq War in 2003, but later described it as "the biggest political mistake of my life", saying he had believed Mr Blair when he claimed to have evidence of Saddam Hussein's weapons of mass destruction.

He became a vociferous backbench campaigner for openness about the causes and consequences of the war, as well as on issues like nuclear disarmament, income inequality, civil liberties and climate change.

His pitch for the leadership after Tony Blair stood down included promises to scrap Trident, renationalise the railways and curb City bonuses, but lasted only a matter of days before he stepped aside to give fellow left-winger John McDonnell a clear run. In the event, Mr McDonnell was unable to secure enough MPs' nominations to get onto the ballot paper and Mr Brown was crowned unopposed.

Unlike some other MPs who nominated Mr Corbyn purely to "widen the debate" in this year's leadership election, Mr Meacher was a committed supporter of the new Labour leader and hailed his victory for offering the right "a very real threat that they've not encountered for the last 30 years".

He recently sparked controversy by suggesting Lord Mandelson should be thrown out of the party for publicly discussing the removal of Mr Corbyn as leader.

Born in Hemel Hempstead in 1939, Mr Meacher was educated at Berkhamsted School in Hertfordshire and took a first in classics at Oxford University before studying at the London School of Economics.

He had two sons and two daughters from his first marriage in 1962 to Molly – now Baroness Meacher – and wed again in 1988 to wife Lucianne, who survives him.