An SNP minister has warned that Scotland is not able to become a “successful, modern independent country in the short to medium term”.

Ben Macpherson, minister for social security in the Scottish Government, further claimed that the transition period following any vote for Scotland to leave the UK could take “many years” or even “potentially decades”.

He argued that Scotland does not currently have the necessary infrastructure to become independent quickly and successfully.

As a result, he told party colleagues: “Any reckless, overly disruptive path to statehood would quickly make our quality of life in Scotland poorer.

“Better to go down a gear and take the journey at a reasonably safe speed than crash trying to rush things.”

His comments came as Humza Yousaf, one of the three candidates to be the next SNP leader and Scottish First Minister, insisted independence could be achieved within five years.

The Scottish Health Secretary told the Sunday Mail: “It can be achieved within five years but that’s going to take persuasion and we’re going to have to give people a hope and a vision.”

However, Mr Macpherson, writing in the Scotland on Sunday newspaper, said: “The fact is – and facts matter – Scotland doesn’t yet have all the necessary 21st century state infrastructure to quickly transition to a successful, modern independent country in the short to medium term.”

He said that “like many others” in the run-up to the 2014 referendum he had believed that making the change to Scotland becoming an independent state would be “doable fairly quickly”.

But he added: “I have humbly since learned the hard reality.”

Mr Macpherson said: “What I have learned from my experience as minister for social security – delivering new Scottish Government benefits and transferring thousands of existing cases from the DWP to Social Security Scotland – is that the practical implementation of constitutional change takes time if it is to be done securely and effectively.

“Wishful thinking and good intentions will not change that, and anyone suggesting there are shortcuts is not being upfront about the practical realities.”

He continued: “In the current circumstances, positive changes of the sort we would want to implement after an independence vote would take years to achieve.

“Following a negotiating period, we would be in a long transitional process with the UK Government for many years, and potentially decades, regarding some matters and system transfers.”

Mr Macpherson said he appreciates that many independence supporters would want “faster progress”, “but it is the responsibility of those of us pushing for constitutional change to make sure an independent Scotland is in the best possible position to start successfully, with the means to do so”.

He added: “More independence, greater social justice, higher economic prosperity and re-entry to the EU are all absolutely achievable, but these things take time.”