The rail union firebrand Bob Crow has saved up to £80,000 in rent by living in a housing association home intended for less well-off people, despite enjoying a six-figure pay package.

Crow’s family is estimated to pay about half the market rent on a three-bedroom property in northeast London even though the former Communist party member earns £145,000 a year.

The boss of the RMT transport union has benefited from a loophole in housing rules. They fail to take into account changes in an occupant’s income once the family has a tenancy.

Separately, it has emerged that the pay of train company chiefs has broken the £1m barrier for the first time while passengers are hit by inflation-busting fare rises.

The disclosure that Crow’s family could have saved up to £80,000 since moving into the end-of-terrace property a decade ago has angered neighbours and exposed him to charges of hypocrisy. Residents said Crow was depriving single mothers and low-paid workers of a home when he could afford to buy his own property.

“With nearly 5m vulnerable people languishing on housing waiting lists, I would have thought a highly paid union baron would feel somewhat awkward taking advantage of publicly subsidised housing,” said Grant Shapps, the Tory housing minister.

Crow’s union has brought parts of the national rail network and the capital’s Underground system to a halt, earning him the sobriquet of “London’s most hated man”.

Recently, the RMT leader has contemplated co-ordinated strikes against changes to public sector pensions and spending cuts. Crow, 49, and his girlfriend, Nicola Hoarau, 47, an RMT official, have lived with their children in a cul-de-sac in Woodford Green since 2001.

The property, which had a convertible VW Beetle parked in its drive on Friday, is owned by London and Quadrant (L&Q) housing association.

On its website, L&Q states: “Our main purpose is to provide high quality, affordable homes ... Most families are on low incomes and usually come to us from the local council lists of those who need housing.”

Crow is not listed by L&Q as a tenant, suggesting that the property is registered to Hoarau or another family member. The family were previously housed by Redbridge council, which has 14,218 people on its housing waiting list, and were transferred to their new home when the local authority allowed L&Q to build on its land.

Under housing legislation, a change in financial circumstances of any occupants is not taken into consideration once a tenancy has been agreed. This explains how Crow and his family can continue to live in the house even though he was paid £145,548 in 2009, the latest year for which RMT accounts are available. This sum included pension contributions and expenses.

Last week other residents said they were paying between £100 and £130 a week in rent on a three-bedroom home. Crow’s rent is estimated at £150 a week because it is an end-of-terrace property. However, a house of a similar size in the private sector in Woodford Green would cost at least £300 a week, according to local estate agents.

This means that over 10 years Crow — who keeps a bust of Lenin in his office and whose dog is named Castro after the Cuban leader — could have saved £78,000 at current prices.

“These houses are supposed to be for low-income families,” said Brenda Barnard, a single mother who lives on the same street as Crow. “There is probably a huge waiting list and he shouldn’t be in there.”

Kay Tomlinson, 34, who lives in a three-bedroom L&Q property around the corner with her two young children, said: “If he’s got a lot of money he should buy a house himself.” Her weekly rent, paid through housing benefit, is £100.

Another woman, who would only give her name as Natasha, said she was paying £100 a week for a one-bedroom flat in an adjoining L&Q block. “It hardly seems fair,” she said.

“The council flats across the road are so overcrowded with families who are desperate for a bigger home and I’ve got friends who have to rent privately because they can’t get onto the housing register in London.”

A taxi driver who did not wish to be named, living on the same street as Crow and paying £130 a week, added: “If he has that much money, I don’t know why he’s living here.”

However, a source close to Crow said he was in an unwinnable position: “You’d have had him by the balls if he was living in a flash mansion.”

Hoarau’s salary is not known, but her appointment as head of the RMT’s credit union caused a cronyism row after she was interviewed by Crow as the sole applicant.

In January, the couple were spotted on the Caribbean island of Aruba during a cruise reportedly costing £800 a head.

The RMT said: “Bob Crow makes no apology for living in social housing at the heart of his local community. He was born into a council house and has lived in one all his life, and actually turned down a union mortgage in favour of remaining a tenant.

“He also turned down the right to buy his council house at a discount, as he believes social housing stock should remain available for future generations.” It was a “slur” to suggest that Crow had profited when he did not set rents.

L&Q said: “The household income details of all those living in social housing may change after they are allocated a property. Such changes do not affect security of tenure or constitute a breach of a tenancy agreement.”