He was a working class activist all his adult life, joining the Communist Party while on active service in the Korean War. He told the story of his break with Stalinism here http://www.spiked-online.com/index.php?/site/printable/1899/
The first time I met Dave was in 1981, during the Workers March for Irish Freedom, which ended with a lobby of the Trade Union Congress at Blackpool. It was at the height of the struggle in northern Ireland, when the Republican hunger striker Bobby Sands had been nominated to stand for parliament. Dave had been secretary of the Thameside Trades' Council, committing it to a policy of supporting the cause of Irish Freedom. In revenge, the TUC sent the up-and-coming apparatchik John Monks to disband Thameside. Dave explained to me that a trade union movement that would not fight oppression in Ireland would not defend its own wages and conditions. He was proved right as Monks climbed the greasy pole to TUC General Secretary while workers saw jobs and wages slashed.
Dave led one of the most militant strikes against redundancy at Lawrence Scotts' engineering company. The strike features in Ken Loach's banned Channel Four documentary Questions of Leadership - though Loach talked to the mostly feeble union officials, not Hallsworth, who led the calls for the occupation of the plant. Eventually, the owners recovered control with a helicopter invasion.
Dave understood that the Labour Party was not a vehicle for defending workers' rights, but a barrier instead. While too many radicals - like Arthur Scargill and Paul Foot - rallied to support the rotten body of the Labour Party - Hallsworth was determined to bury it. In 1987, he stood against the official Labour Party candidate in Stockport. Though the radical left closed ranks against him, he still managed to get thousands of votes.
Dave was a moving orator, who could ham up his labour movement history - once, he addressed a meeting remembering the role that the Manchester workers played opposing slavery in the American Civil War, and one younger comrade, confused on the precise dates of these events assumed that Dave had been there.
Dave was a cheerful host, putting on barbecues for the Manchester branch of the Revolutionary Communist Party. He was a great mocker of other people's excuses, and of his own. His apparently very happy marriage to Elsie lasted more than half a century.
Dave kept an active interest in politics right up to his death, and contributed often to the online journal Spiked. Only months before he borrowed my copy of Douglas Kellner's collection of Karl Korsch's works - returning it with some suitably harsh judgments on Korsch's dilettantism. Only a month ago, he wrote to correct my account of the English publication of Henryk Grossman's book on Marxism, the Law of Accumulation, pointing out that it was he, not 'that bum' Tony Kennedy, that typed up the manuscript on an old Commodore 84, to earn a few pounds extra while on strike.
It was a life that anyone would be proud of, and though Dave often had to fight hard for what he believed in, he was always a cheerful and wise friend. His last email ended like this:
'As the years pass and one morning there is a special shiver in the morning air as the sun rises, you will rekindle your camp fires and restart the great reorganisation of society. What a great day that will be. I'll always be a Socialist dreamer.'