British Airways cabin crew will strike for seven days later this month after failing to reach agreement in a long-running dispute over pay and working conditions, union officials said on Friday.

The Unite trade union said staff would spread the stoppages over a ten-day period between March 20 and March 30 and warned that further walkouts may occur after mid-April.

"Strikes are planned for March 20, 21 and 22 and further on March 27, 28, 29 and 30," senior Unite official Len McCluskey said in a statement.

"There will be no strikes over the Easter period, as we already promised, but further industrial action will be called to take place after April 14 if the dispute has not been resolved," added the union's assistant general secretary.