Talks to end a strike by bin workers in Birmingham have ended without a deal.

The Unite union said negotiations would resume next week, although it offered to continue talking over Easter.

The strike has been running for more than five weeks and the union said a deal “would be much closer” if promises made by the council in interviews were put in writing.

John Cotton, leader of the Labour-run council, said he was “mystified” by the comments, adding the local authority had been very clear that “nobody needs to lose out”.

Hundreds of Unite members began an all-out strike on 11 March in a standoff with the council that has led to bin bags and fly-tipped rubbish piled up on streets.

The pay dispute was initially focused on the council’s plans to remove the Waste Recycling and Collection Officer (WRCO) role, a safety position it says does not exist at other authorities.

However, Unite has more recently urged the council to guarantee bin lorry drivers’ existing levels of pay, particularly with many WRCOs encouraged to take up driving training as a way of protecting their income.

In Wednesday’s statement, the union said: “Speaking to the BBC this morning ahead of fresh negotiations, council leader John Cotton said, ‘we’re in a position where nobody needs to be losing income’.

“If this is true and guarantees were put in writing as part of a new offer, a deal would be much closer.”

Unite said drivers on strike had been told during talks their yearly pay was likely to go down from £40,000 to £32,000.

It stated: “For WRCO workers who do not wish to make a sideways move, the council are saying in public that they will get a one-off payment of £16,000 which would cover two years’ loss of £8,000 in pay cuts.

“Again, if this is true this needs to be put in writing.”

Unite General Secretary Sharon Graham said she stood ready to meet Cotton and Deputy Prime Minister Angela Rayner over Easter.

But she said the council leader should “rethink his position” if his comments “prove again to be untrue”.

“We appear to be in a parallel universe. Yet again John Cotton is saying one thing in public, while his local officers are saying another in the negotiating room and in writing,” she said.

A consultation on plans for compulsory redundancies affecting up to 72 refuse staff began on 3 April.

Cotton said he was keen to see the two parties continue talking so they could bring the dispute “to a close”.

Asked if he had told the union that no-one needed to lose any pay, he said: “We’ve been very clear throughout that there’s a reasonable offer on the table that means nobody needs to lose out and that there are alternative roles available.”

He said the WRCO role was “not sustainable” and the council needed to find a way to remodel its waste service.

“The waste service hasn’t been good enough in this city and needs to improve, which is why we embarked on the transformation process,” he added.

The council has previously said its recycling rate of 22.9% is the lowest of any unitary authority in the country, with the exception of Liverpool.

The government has set a target of reaching 65% in the next 10 years.

Cotton said any agreement with Unite could not cross the council’s “red lines” and create any further equal pay issues.

He also refused to give any guarantees over driver pay and said the role was the subject of an ongoing job evaluation process that was being undertaken across the local authority.

The council leader said he would not comment on a process that “had not been concluded”.

Meanwhile, resident Peter Brookes, who lives in a block of flats in Sparkhill, said his communal bins had not been emptied since January.

He told BBC Midlands Today: “I’m very upset and annoyed. Why can’t they come and collect it?

“Even though they say ‘leave it and we’ll come and collect it the following week’, they never do.

“Soon it will be coming on to the garden. It’s not very nice. Do you want to come out here in the summer, like we have the last few days, and have that in the background with the smell and the flies?”

On Tuesday, the council said the amount of uncollected waste had peaked at 22,000 tonnes, but it was on track to clear the backlog by the weekend.