It follows a report this week which revealed that the recently restored “Waverley” line has been beset by cancellations, delays and unreliable trains.
Mr Yousaf told MSPs at Holyrood yesterday that he has demanded an improvement from the Dutch operator, which holds the ScotRail franchise to run Scotland’s trains, across the whole of the country.
“Within that plan and the actions around it, there is a focus on the Borders route’s performance,” Mr Yousaf said.
“I am closely monitoring and reviewing progress to ensure that better performance is delivered.”
He added: “I am not going to be satisfied until the Borders Railway reaches its public performance measure target and some of the problems are resolved.
“An improvement plan is in place, significant funding is going into that and we are going to give ScotRail the time to ensure that its performance improves. I will monitor that closely and if it does not improve, there will be consequences.”
The report by rail campaigners Bill Jamieson and David Spaven this week said that on only 12 weeks out of 52, ScotRail’s public performance measure target of 92.5 per cent of trains arriving within five minutes of schedule had been achieved for the Edinburgh to Tweedbank service.
But the problems were not all the fault of Abellio, it added. Transport Scotland was behind the “constrained infrastructure specification” for the line, as well as the deployment of Class 158 units – branded the least reliable diesel units in Scotland – for a route with steep gradients and multiple stops.
Borders MSP Christine Grahame said yesterday hit out at the performance of Abellio, insisting that trains were cancelled in 47 weeks out of the past 52.
She added: “In September, the government put in place the recovery plan for the Borders railway yet, on 20 October, three trains were cancelled. One from Tweedbank had to terminate at Newtongrange due to door problems, and even the next day there were two cancellations.”