British Airways is facing further strikes by cabin crew after the latest talks with the Unite trade union failed to reach an agreement.

The Acas conciliation service said that they “regrettably” were unable to break the deadlock and move closer to a deal. This paves the way for another strike ballot, and if cabin crew vote for industrial action then a new wave of walk-outs could begin in the first week of August, the peak of the school summer holiday period.

“At present there are no further meetings planned but Acas will monitor developments and our services remain available,” said Acas.

BA cabin crew workers have staged 22 days of strikes so far this year.

“Unite remains committed to finding a settlement which addresses its members’ concerns,” said a spokesman for the union. “We remain in touch with Acas and with British Airways to that end.”

BA said it remained available for talks.

The industrial action was initiated by changes to staffing levels, but currently centres on the removal of travel concessions from striking workers.

The industrial action has cost the airline an estimated £150m. It recently said passenger numbers were 14.2 percent lower in May than a year earlier.

Cabin crew have so far voted resoundingly for strike action, with majorities of 92.5 percent and 81 percent in two votes. However the harsh reality of living on strike pay – which Unite raised from £30 to £45 a day – as well as BA stripping strikers of discounted air fares, is expected to wield a stronger influence over voting this time.

This month, Unite’s assistant general secretary, Len McCluskey, urged BA to seek an “honourable” settlement.

Union sources claim that both sides are close to a settlement over multimillion-pound reductions in cabin crew costs, but argue that staff travel perks must be reinstated in full for the thousands of crew who joined seven days of walkouts in March and a further 15 days of strikes in May and June.

Members of BA’s 38,000-strong workforce have expressed concerns about the battle with Unite, including a senior pilot who has warned the situation has created “unsustainable” working conditions.