Grant Shapps has told union bosses to “get out of the way” and allow members to vote on newly proposed pay deals.
It comes as fresh strikes take place on London Underground and the capital’s bus system, while national rail is set for more disruption on Saturday.
Speaking to Sky News, the transport secretary claimed that the union leaders were not putting proposed pay offers to their members.
Asked why the strikes have not been resolved, Mr Shapps said: “Because the union bosses won’t put the settlement deals to their members.
“So we’ve had a situation where 8% over two years has been offered – it’s different depending on which piece of the rail we’re talking about here – but broadly speaking.
“And the bosses, for example, the boss of the RMT, simply make the decision without going out to their membership to ask them whether they would like to settle this and get back to work.
“Where it has gone to members – that was in a smaller union called the TSSA – the members overwhelmingly voted for that deal – over 70% [did].
“So it was quite clear that the union bosses are trying to prevent the workers from actually having the offer put in front of them.”
He added: “It’s time for the union bosses to get out of the way and put the deals on the table to their members.”
TSSA union members were on strike on Thursday, and they are set to withdraw labour again on Saturday.
Speaking yesterday, RMT General Secretary Mick Lynch said: “I addressed a meeting of thousands of our members [on Wednesday] night online and they are totally committed to the campaign that we have got.
Read more:
Who is going on strike this month and when
Millions of public sector workers preparing to vote on strikes in ‘biggest wave of industrial action since 1970s’
“They understood the issues when they voted for it and they are showing on the picket lines that they are completely committed to the cause.
“We will keep going until we get a negotiated settlement and our members will decide whether it’s acceptable or not.”
Mr Lynch also said he believed industrial unrest would spread with “generalised and synchronised action” in the face of the deepening cost of living crisis after inflation soared to a new 40-year high of 10.1%.
Mr Shapps said that if unions do not approve modernising changes, they will be forced to do so through a section 188 order.
He added that on pay, the offer on the table was 8% over two years – with unions wanting greater-than-inflation rises.