Senior managers have agreed a 4 per cent pay increase with the operator of the UK’s rail infrastructure, potentially cushioning the blow from strikes later this month.

The Transport Salaried Staffs’ Association on Friday said managers at Network Rail had voted in favour of the pay deal, which also includes better job security and a commitment not to unilaterally change employment contracts.

Although it will not prevent strikes scheduled for August 18 and 20, the agreement should help Network Rail run a skeleton service on those days. About 2,500 other TSSA members at Network Rail plan to take part in the strikes, along with 40,000 workers represented by the RMT union.

Network Rail’s agreement with the TSSA will come as a reprieve to commuters who have been affected by industrial action during the past few months, as railway and London Underground workers continue to protest over pay and working conditions.

However, the union Unite said on Friday that more than 1,600 London bus drivers planned to strike over pay on August 19 and 20. The first day will coincide with a walkout by London Overground and Underground staff.

Grant Shapps, the transport secretary, said the managers’ decision was “fantastic news” and the result of unions working “collaboratively and productively with industry”.

“This acceptance by these TSSA members will mean that we have a strong, reliable contingency staff for any future strikes and will be able to run services for passengers and minimise disruption to lives of everyday people,” he added.

Some of the managers are trained signallers and could step in on strike days to fill the positions, according to one person close to the situation.

Tim Shoveller, who led the negotiations for Network Rail, said he was “pleased” that TSSA’s managers had accepted the offer, which includes a 4 per cent increase on base pay from July as well as heavily discounted leisure travel for employees and their immediate families.

“We believe this is a deal that is both fair for our employees and affordable for passengers and taxpayers,” he added.

The TSSA represents more than 3,000 members at management level working at Network Rail. They had previously voted to take action short of a strike, which would have included not covering for colleagues in the event of a walkout.

These managerial positions include planners, architects and human resources, commercial, compliance, safety management and security staff, among others.

TSSA organising director Luke Chester said that while the deal fell short of the union’s aspirations on basic pay, it addressed many “longstanding concerns”.

“It’s very good news that our union was able to stand up collectively and win concessions across the board from the company, which will really benefit our members,” he said.

He added, however, that it was “a shame that managers had to vote for industrial action before we could make progress. We remain committed to further dialogue with Network Rail to build on these gains and deliver a fair deal for our members going forward.”

Chester also criticised Shapps’s comments, saying that the transport secretary had “some nerve” making comments about working “collaboratively and productively”.

He added that it was the Department for Transport that had been “crippling negotiations” across the rail industry by “preventing companies offering pay rises that reflect the rate of inflation”.

In response, the DfT said it was “extremely misleading to suggest the transport secretary should get involved in these negotiations”.

“The union knows full well that negotiations over pay and working practices don’t happen with the government — they happen with the employers of the people they represent. We once again urge union representatives to get back round the negotiating table,” it added.