Talks could be on the cards between the council and union members in a dispute over plans to sack workers and rehire them on new contracts.

Tower Hamlets and Unison have both said they offered to take part in ACAS mediation in a bid to settle the disagreement over the Tower Rewards scheme.

The council is due to sack staff on July 6 and rehire them on a new contract rejected by union members. Unison says if agreement can’t be reached then strike action is “a possibility”.

The union, alongside the National Education Union, was due to strike in March. The council wanted to impose the contract on April 13 but the coronavirus pandemic forced its delay until July.

The union says now lockdown is easing, the council is continuing with its plan to sack and rehire workers it lauded during the crisis.

It adds members have been left with “no option” but to look at dates for industrial action.

A council spokesperson said staff terms and conditions not updated for more than a decade were changing as part of ongoing improvements.

The package includes measures to increase annual leave for most staff and raise salaries for hard to fill posts. No job cuts are being made.

He said for 15 months Tower Hamlets has tried to reach collective agreement with the trade unions and has changed the package following feedback from unions and staff.

“However, Unison has consistently been reluctant to engage, unwilling to compromise and has not offered any viable alternatives. We have offered to try and resolve our dispute with the support of ACAS and are pleased that the trades unions have agreed to participate in this process.

“It has always been our intention to reach a collective agreement and we remain hopeful of doing so to avoid any unnecessary industrial action.”

But Unison accused senior managers of turning up the “duress dial” with council staff recently receiving a letter seen by the Advertiser using words the union says many members found threatening.

It describes the move as “a blatant attempt to harass, mislead and intimidate” workers into signing up so the council can raise the contract’s “voluntary” acceptance rate.

Tower Hamlets denied the letter was a threat, saying it was a reminder of the start date and attempt to understand workers’ reasons for not accepting new terms and conditions or why they are working under protest.

Staff who do not sign the contract and go to work will be still be employed, the council spokesperson said.

A worker, who received the letter but asked not to be named, said: “Having spent the last few months assisting the most vulnerable, I’m well aware of the dangerous impact a strike would have on the people of Tower Hamlets, but the council are setting us on course to use this last ditch attempt to maintain our working conditions.”

Unison says staff will not accept a Labour council imposing a contract which they believe worsens their terms and condition after working so hard during the pandemic and sometimes at risk to their health.