Following his return to the cabinet after a six-year absence in October, Mr Harper has found himself embroiled in a row over pay for rail workers, with strike action being planned over four days in the lead up to Christmas and again in January.
And after all parties failed to reach an agreement during emergency talks on Monday (December 5), a further three days of industrial action was announced for December 24-27.
The RMT - representing workers at 14 train companies - wants to see pay increase in line with the rising cost of living, long-term job security and better working conditions for rail workers.
The Rail Delivery Group (RDG) - representing the train companies - had offered workers a four per cent pay rise this year and another four per cent next year in an attempt to settle the dispute at the weekend.
But that offer was rejected, with RMT general secretary Mick Lynch saying the proposal would be unacceptable to members.
That followed talks between Mr Lynch and Mr Harper two weeks ago, after which the RMT general secretary criticised the government’s “astonishing” lack of urgency after more than a week went by without an offer being made.
In a statement following the rejection on Sunday (December 4), Mr Harper said: “The RMT has been offered an improved new deal by the train operating companies and has rejected it outright. The situation is incredibly disappointing, and unfair to the public, passengers and the rail workforce who want a deal.
“Our railways need to modernise. There’s no place for outdated working practices that rely on voluntary overtime to run a reliable 7-day service.
“Passengers should also receive the service they’ve paid for. This deal will help get trains running on time.
“The Government continues to play its part in trying to facilitate a resolution to this dispute, while rightly letting the employers do the negotiating. Now it’s for the unions to play their part too by putting the offer from the train operating companies to their members and call off industrial action that would damage the rail industry, rail workers and the wider economy.”
In addition to the walkout at 6pm on December 24, industrial action will take place over 48 hours on December 13-14 and 16-17, and January 3-4 and 6-7.
On Sunday’s offer from the RDG, Mr Lynch said: “We have rejected this offer as it does not meet any of our criteria for securing a settlement on long term job security, a decent pay rise and protecting working conditions.
“The RDG and DfT who sets their mandate, both knew this offer would not be acceptable to RMT members.
“If this plan was implemented, it would not only mean the loss of thousands of jobs but the use of unsafe practices such as DOO and would leave our railways chronically understaffed.”