A public sector body "will be ready" to take over the ScotRail franchise by 2020, the Scottish Government has said.

The move would be made if the current operator of the franchise, Dutch transport firm Abellio, does not have its contract renewed for another five years.

As part of the package of new powers delivered to the Scottish Parliament after the 2014 independence referendum, the Scottish Government has the power to award the franchise to a public sector operator.

A Scottish Government spokesman said: "Using new powers awarded in March of this year, Transport Scotland officials have started the work necessary to fulfil the commitment to ensure that a public sector body is in a position to bid for the next franchise.

"We will ensure that a public sector bidder is ready should either we or Abellio ScotRail take steps to invoke the break point in the current contract."

Abellio's performance has been criticised since it took over the service from First Group in 2015.

Latest statistics show 90% of trains at Glasgow High Street, Arbroath, Ardrossan Harbour and Arbroath stations are late.

A further 22 stations have more than half of their services running behind schedule.

Under its contract with the Scottish Government, Abellio is expected to ensure 91.3% of trains arrive at their destination within five minutes of their scheduled time.

The latest performance figures show the firm is currently running at 89.6% of trains arriving either on time or under five minutes late.

Transport minister Humza Yousaf said: "I don't find the performance level acceptable at all. They have put in an improvement plan and I'll work with them. We'll monitor it to see how it progresses.

"But make no mistake about it, if that improvement is not forthcoming, there's a reason why we have a break clause in the contract."

Earlier this month, around 19,000 commuters signed a petition calling on the Scottish Government to strip the contract from Abellio.

A spokesman for Abellio said: "In Abellio we have long understood that the Scottish Government had every intention of seeking a public sector bidder for the next ScotRail franchise.

"We remain fully focused in getting on with the job of delivering a national railway fit for Scotland and our customers."