Dominic Cummings' family must start to pay council tax on the bolthole he escaped to with his wife and child at the height of the coronavirus lockdown, a Government agency has ruled. However, they escaped nearly 20 years of back taxes on the property, on the family's farm in Durham, which could have left them with a bill running to several thousand pounds. Mr Cummings, the Prime Minister's chief adviser, was accused of breaking lockdown rules when he drove 260 miles to the farm from his London home after his wife became ill with suspected coronavirus on March 27, a day before he also fell ill. He later described the property as "an isolated cottage on my father's farm" during a press conference in Number 10's garden and insisted he had done nothing wrong because the rules allowed him to look after a child in exceptional circumstances. In June, Durham County Council found there had been "historical breaches" of planning and building control regulation during the construction of the property and the conversion of another into two homes. At the time, the council said it could not take enforcement action against the family because of a time limit on such measures and referred the matter to the Valuation Office Agency. The agency's ruling means that, from this month, the Cummings family will have to pay three separate council tax bills for the homes at North Lodge instead of the one bill they have been paying until now, The Guardian reported. John Hewitt, the council's director of resources, said: "The current single assessment [for council tax on North Lodge] will be replaced with three entries in the rating list going forward. These changes will be implemented with effect from October 4 2020, which is the date we have been instructed to apply the changes from. "The day on which the rating list is to be amended is a matter for the Valuation Office Agency." A spokesman for the Valuation Office Agency told The Telegraph: "We treat all taxpayers equally and we value domestic properties in line with legislation. We cannot comment on individual cases." A Downing Street spokesman declined to comment.