THE Home Office waged a seven-year war against its own tax rates, attempting to shave nearly £16 million off the amount it pays for its headquarters, official documents show.

Valuation tribunal decision documents disclosed today show that the Home Office first lodged an appeal against the £25 million rateable value in 2010, hoping to slash it down to £19.1m, but that was dismissed in March.

The department eventually lost its lengthy battle against the level of property taxes it pays for the site at 2 Marsham Street in Westminster earlier this year.

If it had been successful, it would have been handed a £15.75m rates rebate.

Prime Minister Theresa May was in charge of the Home Office throughout most of the challenge, in her previous role as home secretary.

Mark Rigby, chief executive of business rent and rates specialists CVS, said the Home Office revelation makes a mockery of the new appeal rules.

But a Home Office spokesman said it had launched an appeal against the latest decision on grounds of “best commercial practice.”