He was urged to fully scrap merger proposals as he set out further details of alternative options to integration.
In a letter to Holyrood’s justice committee, Mr Yousaf said the medium-term option being developed is to set up a new committee to oversee railway policing in Scotland, involving members of the oversight bodies of both police organisations.
This could be created under existing legislation, without the need to enact the Railway Policing (Scotland) Act 2017.
A path was cleared for the merger when this law was passed in June 2017 despite criticism from opposition parties, unions and others.
Integration was originally due to take place in April, but the timetable was delayed. Mr Yousaf said in September it might never be enacted.
Now, Mr Yousaf said the British Transport Police Authority (BTPA) and the Scottish Police Authority have started to work together on the medium-term committee option.
“The medium-term option identified presents a potentially viable model to swiftly and effectively enhance the governance and accountability of the delivery of railway policing in Scotland,” his letter states.
“The Scottish Government remains committed to keeping the commencement date of the Railway Policing (Scotland) Act 2017 under review and clearly such considerations will take into account how the proposed medium-term option is operating in practice.”
Mr Yousaf said he recognised the need to “give clarity to BTPA staff and officers” and was keen to progress quickly.
Scottish Conservative justice spokesman Liam Kerr said: “The SNP’s dogmatic pursuit of the BTP merger has wasted a huge amount of time and money, while creating an astonishing level of confusion and uncertainty for transport officers.
“The SNP now need to take a full merger off the table altogether so that jobs, pensions and passenger safety are all protected.”
Scottish Labour justice spokesman Daniel Johnson said Mr Yousaf “must now confirm a full merger will never be carried out under his watch”.
He said: “A failure to do so will cause further stress for staff who have already endured years of uncertainty over their future.
“This saga has been an extraordinary waste of the Government’s time and taxpayers’ money and it is time for the SNP to finally bring it to an end.”