The former British deputy prime minister John Prescott has died aged 86, his family has announced.

His family said he had “spent his life trying to improve the lives of others, fighting for social justice and protecting the environment”.

The former trade union activist and ex-merchant seaman had Alzheimer’s and died “peacefully” surrounded by relatives at his care home, they said.

Prescott was a key figure of Tony Blair’s New Labour project, seen by many as custodian of the party’s traditional values in the face of a modernising leadership.

He was ennobled in 2010 and introduced to the upper chamber as Lord Prescott of Kingston upon Hull having served for four decades as an MP for the city.

In a statement released after his death, his wife, Pauline, and sons Johnathan and David said that representing the people of Hull had been “his greatest honour”.

“We are deeply saddened to inform you that our beloved husband, father and grandfather, John Prescott, passed away peacefully yesterday at the age of 86,” they said.

“He did so surrounded by the love of his family and the jazz music of Marian Montgomery.

“John spent his life trying to improve the lives of others, fighting for social justice and protecting the environment, doing so from his time as a waiter on the cruise liners to becoming Britain’s longest serving deputy prime minister.

“John dearly loved his home of Hull and representing its people in parliament for 40 years was his greatest honour. We would like to thank the amazing NHS doctors and nurses who cared for him after his stroke in 2019 and the dedicated staff at the care home where he passed away after latterly living with Alzheimer’s.

“In lieu of flowers and if you wish to do so, you can donate to Alzheimer’s Research UK.

“As you can imagine, our family needs to process our grief so we respectfully request time and space to mourn in private. Thank you.”

Prescott ceased to be a member of the Lords in July this year after facing health difficulties.

He had only spoken once in the chamber since having a stroke in 2019, official records show, and had not voted since February 2023.

Over a parliamentary career spanning more than half a century, Prescott served for 10 years as deputy prime minister after Labour’s 1997 general election landslide.

At times short-tempered, he once famously punched a protester who threw an egg at him during an election campaign visit to north Wales in 2001.

But during much of his time in office, he acted as a mediator in the often turbulent relationship between Tony Blair and his chancellor, Gordon Brown.

He also oversaw the environment, transport and the regions, a brief that included helping to negotiate the international Kyoto protocol on climate change.

Prescott was a loyal supporter of Blair in office but subsequently critical of parts of New Labour’s legacy, denouncing Britain’s involvement in the Iraq war.

He also strongly defended Jeremy Corbyn during his time as party leader in the face of fierce criticism.

Born in Prestatyn in Wales on 31 May 1938 the son of a railwayman, Prescott left school at the age of 15 to work as a trainee chef and then as a steward on the Cunard Line before entering politics.

In a private letter in 2007, Blair said his former deputy’s role “smoothing out problems, sorting out colleagues and troubleshooting” had been an “integral part of getting things done”.

The former prime minister said: “The completely unique Prescott blend of charm and brutality – made always more effective by the unpredictability of which would be predominant – got you through the decade, kept the government together and above all, gave me a lot of fun. I was lucky to have you as my deputy.”