The government has approved an EU ruling to abolish the acre as a rule of measurement.
From January 2010, farmers and land owners will have to use hectares instead of acres, one of Britain’s oldest units of measurement.
The UK previously had an opt-out from using some of the EU’s metric measurements, but Junior DEFRA minister Jonathan Shaw signed an agreement to switch to hectares at a low-key meeting in Brussels last week.
Conservative MPs have criticised DEFRA over allowing Mr Shaw to represent the UK’s interests when other EU countries sent cabinet minister.
Shadow Europe minister Mark Francois said abolishing the acre was “pointless interference” and was a matter for the UK to decide on.
“The government needs to think again and insist that we must keep our right to use our ancient traditional measure of land if we wish.”
Andrew Shirley, head of rural research at Knight Frank, said banning the acre would make little difference to selling land and farms.
“The acre, however, is a measurement that many farmers feel comfortable with and understand so it seems to make little sense to stop people from using it.
“It is probably up there with the pint and mile as one of the great British units of measurement and whatever Brussels or Whitehall say I don’t think that will ever change.”