The Rail, Maritime and Transport union (RMT) should get “off the picket line and round the negotiating table” as passengers face fresh disruption from strikes, Transport Secretary Mark Harper has said.

Around half of Britain’s railway lines are closed and only a fifth of services are running as tens of thousands of workers at Network Rail and train operators stage two 48-hour walkouts starting on Tuesday and Friday.

Many places have no services, including most of Scotland and Wales.

Drivers in the Aslef union will strike on Thursday.

Picket lines have been mounted outside railway stations across the country in a repeat of what became a familiar sight last year.

Mr Harper told Times Radio: “There is a very fair pay offer on the table which has been accepted by two of the trade unions on Network Rail.

“The RMT recommended that their members didn’t accept it, but actually a third of their members still voted in favour of it.

“I think it is time that the RMT got off the picket line and round the negotiating table to try and hammer out a deal with the train operating companies and Network Rail.”

The minister insisted he has had “perfectly constructive discussions” with all rail union leaders when asked if he has a good relationship with RMT general secretary Mick Lynch.

Mr Harper told ITV’s Good Morning Britain that more meetings with the rail unions will take place next week.

He said: “I would, frankly, rather they were taking place this week rather than the strikes happening, but that was a matter for the unions.”

Speaking to the PA news agency from an RMT picket line outside London Euston station, Mr Lynch said: “The Government and the companies have not put any fresh proposals to us.

“They know what needs to be done to move towards a settlement, how to work through the problems and get to some documentation that we can all support, but that’s not happened so far.

“We’re hoping in the next few days that they will come to us and propose more meetings and more sessions of negotiation but at the moment that’s simply not there.

“The Government has let these strikes go ahead and that’s unfortunate.”

He added: “We would like to get into a situation where we’re negotiating constantly with the companies and where we didn’t have to have strike action, and then work up a settlement that our members could vote on and accept.

“But if we don’t get that there will have to be more action, and we’ve got a mandate that runs through to May this year, and if we have to go further, that’s what we’ll need to do.”

Tim Shoveller, Network Rail’s chief negotiator, said the Government-owned company wants to “work with the RMT now to make clarifications where there’s been misunderstanding” with the rejected offer, and put it to another vote.

He told BBC Radio 4’s Today programme: “We only need 2,000 people who voted no last time to change their vote and the deal will pass.

“So, we think that’s within touching distance.”

Location technology company TomTom said traffic congestion in some cities increased slightly at 8am Tuesday morning compared with the first working day of 2022.

They include London (up from 22% to 27%), Birmingham (up from 23% to 30%) and Liverpool (up from 20% to 24%).

The figures represent the proportion of additional time required for journeys compared with free-flow conditions.

Passenger footfall was down 84% on Tuesday compared with the average Tuesday, data from 20 Network Rail managed stations shows.

Some 131,613 people passed through the stations, compared with 846,054 passengers on the last “normal” Tuesday, December 6.