The former president of the Union of Democratic Mineworkers had denied 14 charges of theft from Phoenix Nursing and Residential Home Ltd, a subsidiary company of the UDM charity Nottinghamshire Miners Home.
But a jury at Nottingham Crown Court unanimously found him guilty of stealing £148,628.83, some of which was used to carry out improvements on his home, including a £11,750 kitchen and other building and landscaping work.
UDM general secretary Mick Stevens, who was accused of the same charges, was cleared of any involvement by the jury.
Judge John Wait, told 61-year-old Greatrex: “You have been convicted of a series of serious frauds against union members who had placed their trust in you. I see only one possible sentence – to spell it out, that is a prison sentence.”
Greatrex, of Shepherds Lane, Stanley, Nottinghamshire, was released on conditional bail to be sentenced at the end of May after reports have been prepared.
Between 2000 to 2006 he billed the charity for improvement work, which was in fact being done on his own property.
The court heard details of invoices paid to four different building firms for work, such as installing a new kitchen and cutting down trees at Greatrex’s home, which totalled £148,628.83.
Greatrex spent more than 20 years in the National Union of Mineworkers before forming the UDM in 1985. He became a controversial figure for speaking out against NUM president Arthur Scargill’s tactics in the 1985 strike. He formed the UDM claiming that nobody was speaking out for Nottinghamshire miners, prompting a split between workers.