Some 53% of more than 33,000 GP members voted in the BMA ballot, with 79% backing industrial action short of a strike. Among consultants, 84% backed the move, along with 92% of junior doctors.
GPs have been advised to open practices as usual, but offer emergency-only services and halt routine paperwork that can safely be delayed.
A backlash began in national newspapers the day after the ballot, with headlines accusing doctors of greed and selfishness. Health secretary Andrew Lansley ruled out fresh talks and claimed the public would not understand or sympathise with BMA industrial action.
The BMA sought to hit back with full-page adverts in national newspapers setting out why doctors felt compelled to take action.
Reforms in 2008 made the NHS pension scheme 'fair and sustainable', the letter from BMA chairman Dr Hamish Meldrum argued. The BMA has said the NHS pension scheme provides a £2bn annual surplus to the government, and that cuts and government plans to increase doctors' contributions to 14.5% would leave them paying twice as much as civil servants on similar pay for equivalent pensions.
Speaking after the ballot results were announced, Dr Meldrum said: 'The government has effectively torn up a fair, sustainable and affordable deal on NHS pensions reached only four years ago and has refused to negotiate seriously on any further changes.'
GP leaders said practices must inform their PCT if they wish to take part in industrial action. GPC deputy chairman Dr Richard Vautrey said GPs should make sure they have no appointments or clinics booked for 21 June. 'Practices will need to cancel or postpone clinics, such as minor surgery clinics, as well as other booked appointments on the day,' he said.
GPC chairman Dr Laurence Buckman emailed all GPs advising them to identify a lead person to co-ordinate the action and liaise with the BMA.
He urged practices to plan how they would work if not all their doctors participate.
BMA pensions committee deputy chairman Dr David Bailey said the BMA was prepared to take further action if the government did not change its stance after 21 June.
More than two thirds of doctors backed full strikes in the ballot, a move the BMA has ruled out but asked doctors to vote for to boost legal protection.