Planned industrial action by more than 1,500 bus drivers over hot weather working conditions has been put on hold.
Unite members at Arriva North London took strike action on Friday and Tuesday in protest over high temperatures.
Further strikes set for Wednesday to Friday were suspended after talks yielded a fresh offer on terms, allowing drivers to vote on the deal.
Unite warned that should the proposal be rejected, strikes will resume on Tuesday 25 August.
Unite regional officer Steven Stockwell said: “Following talks, Arriva has made an offer to Unite members.
“To allow our members to have their say on whether to accept this, we have postponed strike action so they can be balloted.”
Industrial action by members of the Unite union employed by Arriva North London was due to run intermittently until 4.30am on Friday 21 August.
The drivers are taking 26 days of action over what they say is Arriva North London’s failure to act on working conditions during extreme heat.
Drivers from eight bus garages – Barking, Edmonton, Enfield, Grays, Palmers Green, Stamford Hill, Tottenham and Wood Green – are involved in the dispute.
The union says that most Arriva buses operate with air cooling systems rather than air conditioning, leaving drivers exposed to extreme temperatures during the recent series of heatwaves.
Unite is calling on Arriva to fit all buses with effective air conditioning, arguing that working in scorching temperatures is dangerous for drivers, whose cabs can reach highs of more than 40 degrees.
Such temperatures can cause health issues including heatstroke and exhaustion, fatigue, dehydration and dizziness.
The industrial action comes after a summer in which the UK has struggled with drought and extreme heat.
On Thursday, 13 August, the Met Office reported the hottest day of the year so far with temperatures surging to 38.1C at Kew Gardens in West London.
“Extreme heat is creating challenges across many sectors, including London's bus network,” Wasim Mohammed, managing director of Arriva London, told .
“The wellbeing of our colleagues and customers is our top priority, and we are working closely with Transport for London (TfL) to ensure appropriate support is in place.
“We have already introduced additional support for drivers during hot weather, including regular breaks and welfare checks – and are continuing to invest in long-term improvements, including upgraded air conditioning systems and new buses coming into our fleet.
“These upgrades are complex and being led by TfL as part of its extreme heat taskforce. We urge Unite to come back to the negotiating table and engage with us constructively so we can avoid further disruption.”
Lorna Murphy, director of buses at TfL, apologised for the disruption. “We know that any disruption to London's bus network can have a significant impact on our customers, and we're working closely with Arriva to help customers travel during these periods of strike action,” she told .
“We encourage anyone travelling in the affected areas to plan ahead, allow extra time for their journeys, and check before they travel using the TfL Go app or our website.”