A deal could be close to end the long-running RMT strikes on the railway, industry bosses have told MPs, adding that customers’ confidence is “ebbing away” as they start to switch to rival modes of transport.

Network Rail said the chances of a settlement with the union were “seven out of 10”, with just 2,000 more staff members to persuade to accept. However, the train drivers’ union, Aslef, said there was “zero” chance of an agreement in its separate dispute.

In its own evidence to the Wednesday’s committee hearing, rail union leaders said the government had “sabotaged” negotiations and their members would not accept deals that enforced changes to terms and conditions along with real-terms pay cuts.

The prospect of progress in resolving the dispute with Network Rail – where strikes have been most prolonged, and where the RMT action has had most impact through its signalling staff – appears to be higher than with train companies and drivers.

A deal worth 9% over two years, with guarantees on jobs and other benefits, was rejected in an RMT referendum before Christmas, although the smaller numbers of staff in the TSSA and Unite unions accepted.

Tim Shoveller, the lead negotiator for Network Rail, told MPs that 36% of RMT members had voted yes – and that some key issues and questions had not been fully explained before the first vote. He said: “It’s a couple of thousand people that need to change their vote … I think there’s every chance by some very carefully targeted discussions at achieving that.”

Shoveller said he had met RMT leaders on Tuesday for discussions and they were planning to meet again next week. Questioned where he would rate the chances of a deal on a scale of one to 10, he said seven.

However, answering the same question earlier, the Aslef leader, Mick Whelan, replied “zero”, adding: “We’re further away than where we started.” Whelan said his union’s executive would examine a proposed offer next Monday, but he expected them to reject the deal sent out on Friday that “crossed our red lines and smashed our enabling agreement”.

He said that the offer was a 20% real-terms pay cut, given inflation and the years without a rise, and worse conditions: “How could any trade union sell this to anyone they represent?”

Whelan said unions were “in it for the long-haul”, adding: “Our members will do this for as long as it takes, to protect their futures.”

Steve Montgomery, the chair of the Rail Delivery Group and the lead negotiator for train operators, said the dispute was “hurting the industry”. He said: “We are seeing customer confidence ebbing away every day – we are seeing it when strikes happen, the disruption with action short of strikes when people don’t become available to cover – these things are all impacting and customers are starting to use other modes of transport.”

The RMT general secretary, Mick Lynch, accused the government of “deliberately torpedoing” talks by inserting clauses in a deal from train operators in December that included driver-only operation. He told MPs: “It’s sabotage. They wanted the strikes to go ahead … they didn’t lift a finger or a telephone over Christmas to stop them.”

He said there was “almost a Stalinist obsession in the Department for Transport” (DfT) with controlling the rail industry, and that “British Rail would never have tolerated that level of interference”.

Questioned by the Conservative MP Greg Smith on whether strikes were driving people off the railway, Lynch said the government should shoulder the blame.

Lynch said: “Loads of damage is being done – but the damage is being conceived and controlled in the DfT. The damage has been envisaged in Whitehall; by people who know very little about the railway. It is being caused by the reckless policy of the current administration – not by the workforce.

“What about the days when we’re not on strike, when it’s absolutely useless as well?” he added.