MSPS are set to discuss putting a merger of the transport policing north of the border and Police Scotland on hold.
The Conservatives want a vote on the issue due to concerns over “leadership challenges” facing the single force.
The party’s justice spokesman, Liam Kerr, also highlighted the importance of railway policing to public safety, particularly terrorism.
His debate motion states due to these concerns “therefore that it would be prudent to pause the integration of the British Transport Police (BTP) into Police Scotland”.
Legislation to merge British Transport Police in Scotland with the single force was passed at Holyrood in June.
Senior officers from Police Scotland and BTP said on Tuesday the forces would not be fully integrated by the deadline of April 2019.
BTP Chief Superintendent John McBride told staff in a statement a full merger by that date “will not be possible” and government officials will be informed of the view at a meeting on January 30.
He said Police Scotland have put forward an alternative proposal of “operational integration” which would rely on BTP in areas such as IT, funding and data access.
Acting top police officer Deputy Chief Constable Iain Livingstone, who is standing in for Chief Constable Phil Gormley while he is on special leave for an investigation into misconduct allegations which he denies, told the Justice Committee there were “significant issues” which would not be resolved by the deadline.
The controversial proposals for integration attracted widespread opposition with opponents raising safety concerns but the Scottish Government said the merger would approve accountability and the safety would remain the top priority.