British coal miners who want to end the 23-week-long strike in their industry have named a ''D-day'' for a return to work in defiance of trade union leaders. The back-to-work guerrilla strategy, devised by a miner with the code name ''Silver Birch,'' is keyed to Sept. 3 - when the Trades Union Congress gathers in Brighton for its annual meeting.
On that day in Yorkshire, south Wales, Scotland, and Kent, miners who want to bring the strike to an end plan to return to their pits and attempt to work normally. They hope other miners will follow them.
''Silver Birch,'' otherwise known as Christopher Butcher, is a miner from Nottinghamshire, where the strike called by union militants has failed to take hold.
He has emerged as an informal leader of antistrike miners in other coal fields. Mr. Butcher organized a secret meeting of like-minded miners who decided that without a deliberate strategy on their part, the majority of pit workers would stay away from the coal face because of union intimidation.
The D-day strategy, already denounced by Arthur Scargill, leader of the National Union of Mineworkers (NUM), was made public after a conference of miners' representatives decided to prolong the strike. Mr. Scargill attacked attempts to break the strike and refused to condemn violence on the picket line - a tactic used to prevent a return to work.
Scargill has consistently refused a national pithead ballot by NUM members, arguing that, apart from Nottinghamshire, the pro-strike views of his union's rank-and-file members were already clear.
While Silver Birch was making his D-day arrangements, two other miners approached the courts for an order to require Scargill and other left-wing leaders of the miners to hold a pithead ballot. The case was expected to last some weeks.
Silver Birch's campaign has caught the public imagination. It has also attracted financial support from business interests eager to see the strike come to an end.
Companies have supplied the antistrike miners enough money to print posters, travel through the coal fields, and organize a challenge to Scargill. The D-day campaign has been discreetly welcomed by the chairman of the National Coal Board , Ian MacGregor, and by the Thatcher government.
Mr. MacGregor hoped for a steady drift back to work as the families of striking miners realized the strike could not be won. He now realizes that without an extra stimulus there may be little chance of such movement in the near future.
Initially the D-day strategy will focus on three coal pits in Yorkshire, the county where the strike is most effective. Discontent with Scargill's policies is believed to be strongest at those three pits.
Silver Birch hopes to persuade at least 20 miners to enter each pit and begin working normally. Then a call would be issued for strikers to join them underground.
The antistrike miners expect to meet determined and probably violent opposition on Sept. 3. It is almost routine for striking miners to attack vehicles taking working miners to the pits.