Former Labour minister and crossbench peer Frank Field has died at the age of 81, his family has announced.

Lord Field of Birkenhead died in a London care home on Tuesday night following a “long battle with cancer”, and is survived by two brothers.

He revealed he was terminally ill in October 2021 and had spent time in a hospice when a statement from him was read out in the House of Lords calling for laws on assisted dying to be relaxed.

A statement from Lord Field’s family, issued by his Parliamentary office and posted on X, formerly Twitter, said: “Through a long battle with cancer, Frank Field remained resilient and engaged with life until the end.

“He will be enormously missed by his family and wide circle of friends.

Frank was an extraordinary individual who spent his life fighting poverty, injustice and environmental destruction

“Frank was an extraordinary individual who spent his life fighting poverty, injustice and environmental destruction. His decency and faith in people’s self-interested altruism made a unique contribution to British politics.

“After 40 years of dedicated public service, Frank will be mourned by admirers across the political divide. But above all, he will be deeply missed by those lucky enough to have enjoyed his laughter and friendship.”

Tributes from the veteran politician’s colleagues have poured in from across different parties.

Commons Speaker Sir Lindsay Hoyle called Lord Field a “formidable MP” who was “neither cowed by the establishment or whips”, and was the “driving force” behind Parliament’s commitment to prevent slavery and human trafficking within its supply chains.

“Having worked with him on the modern slavery advisory group, and made him its chair, I am in no doubt his efforts saved many lives nationwide from this shameful criminal activity,” the Speaker said.

What a blessing to have known him and benefited from his advice and kindness, even as his illness gripped him

Labour leader Sir Keir Starmer said Lord Field had “dedicated his life to being a voice for the vulnerable and marginalised people in the country”.

He described the senior politician as “principled, courageous, and independent-minded” and said his “honour and integrity were well known and admired”.

Shadow Commons leader Lucy Powell said Lord Field “taught and helped me greatly” and recalled working with him on early years and education, adding that he made a “massive impact” on the lives of many children.

Shadow health secretary Wes Streeting said: “Rest in peace, Frank Field. A great parliamentarian, crusader for social justice and source of wise counsel.

“What a blessing to have known him and benefited from his advice and kindness, even as his illness gripped him. Deepest condolences to all who knew and loved him.”

Former home secretary Dame Priti Patel said he had an “unwavering moral compass”.

“My thoughts and prayers are with the family of Frank Field,” she said. “Frank was a kind and compassionate man and a great Parliamentarian.

“His unwavering moral compass, commitment to working cross-party and unshakable principles defined him and will be greatly missed.”

Veteran Labour MP Harriet Harman said: “At Frank’s core was the conviction that poverty was never to be accepted and could be ended. Clever, persistent and caring, he held that argument high across decades RIP.”

And Labour former minister Dame Angela Eagle said: “Very sad news. Always supportive of me as his Parliamentary neighbour, brimming with ideas to make society better – a great champion of his Birkenhead constituents: RIP Frank”

Former Green Party leader Caroline Lucas said she was “sad” to hear of Lord Field’s death.

“Frank commanded respect on all sides of the House with his kindness, decency and commitment to the common good,” she added.

Sir Tony Blair, the former Labour prime minister, said Lord Field was an “independent thinker never constrained by conventional wisdom, but always pushing at the frontier of new ideas”.

Whether in his work on child poverty or in his time devoted to the reform of our welfare system, he stood up and stood out for the passion and insight he brought to any subject

He added: “Even when we disagreed, I had the utmost respect for him as a colleague and a character.

“Whether in his work on child poverty or in his time devoted to the reform of our welfare system, he stood up and stood out for the passion and insight he brought to any subject.”

The Child Poverty Action Group, a charity at which Lord Field had served as director, described him as a “true champion for children and low-income families”.

“As CPAG director, Frank also helped pave the way for the minimum wage, free school meals and rent allowances for low-income families, all fundamental social protections,” its chief executive Alison Garnham said.

Lord Field took his seat in the upper chamber in October 2020 after being elected 10 times to represent Birkenhead between 1979 and 2019.

He served as welfare reform minister in the first Blair government in 1997 with a remit to “think the unthinkable” and went on to chair the Work and Pensions Select Committee.

He remained in the post of welfare reform minister for little over a year following policy clashes with the prime minister and then-chancellor Gordon Brown.

Sir Tony stated in his memoirs that instead of thinking the unthinkable, Lord Field had ended up “thinking the unfathomable”.

Lord Field was also a member of the Labour Leave group.

He, along with three Labour colleagues, sided with the Conservatives in a crunch Brexit vote in 2018.

It saw him accused of betrayal, leading to him losing a no-confidence vote within his Birkenhead Constituency Labour Party, although he insisted he was defending working-class Brexit voters.

He later resigned the Labour whip over antisemitism and “nastiness” in the party under Jeremy Corbyn’s leadership.

Last February, the peer was cheered as he made his first appearance in the House of Lords for almost two years, arriving in the chamber in a wheelchair to pledge allegiance to the King.

He had told the Observer of his determination to take the oath to the King – something all peers are obliged to do after the death of a monarch.

The politician was made a member of the Order of the Companions of Honour in the 2022 New Year Honours, describing it at the time as a “terrific privilege”.

The acknowledgement of Lord Field’s public and political service followed a career in which he showed support for causes including pensions reform, ending child poverty and stamping out modern slavery.

He served on the boards of the charities Cool Earth and Feeding Britain, as well as the Frank Field Education Trust.