The carrier is axing the flights until the end of October because it cannot guarantee its schedules during staff shortages and ahead of expected strikes over pay and conditions by its own staff.
The latest cuts mean BA has removed 13% of its planned capacity. Long-haul remains unaffected.
BA said: “The whole aviation industry continues to face into significant challenges and we’re completely focussed on building resilience into our operation to give customers the certainty they deserve.
"The government recently decided to give the whole industry slot alleviation to minimise potential disruption this summer. While taking further action is not where we wanted to be, it’s the right thing to do for our customers and our colleagues.
"This new flexibility means that we can further reduce our schedule and consolidate some of our quieter services so that we can protect as many of our holiday flights as possible.
“While most of our flights are unaffected and the majority of customers will get away as planned, we don’t underestimate the impact this will have and we’re doing everything we can to get their travel plans back on track.”
BA revealed the latest cuts less than 24 hours before unions representing 700 of its check-in and ground-handling staff at Heathrow were due to reveal strike dates in a dispute over pay.
The walkouts are widely expected to coincide with the start of the summer peak.
