Increasing charges for students coming to Scotland from the rest of the UK is "tough but necessary", the body which represents universities north of the border has stated.
Universities Scotland defended the change, which will see students from England, Wales and Northern Ireland paying up to Â£9,000 a year from the academic year 2012-13.
The Scottish Government is moving forward with legislation to allow universities north of the border to increase fees for students from the rest of the UK.
And in a submission to Holyrood's Education Committee ahead of a meeting today, Universities Scotland described the proposed new fees regime as being "a tough but necessary decision".
It added: "We stand by this policy as the best outcome in a difficult set of circumstances.
"It offers the best way to achieve important policy objectives for Scottish students and Scottish universities."
Universities Scotland argued that if fees for students from the rest of the UK had not been increased, students could view universities north of the border as being a "cheap option".
It said: "The availability of places for Scottish domiciled students at Scottish universities would have been under real threat had the rest-of-UK fees level not been increased from the current rate of Â£1,800 (Â£2,800 for medicine). There are over 520,000 university applicants in the rest of the UK compared to 43,000 Scottish domiciled applicants. If Scotland had been perceived as the cheap option across the UK this would have placed untenable pressure on Scottish students competing for places at Scottish universities.
"The Scottish Government, Scottish universities and Scottish student representative bodies could not have let this happen."
Alastair Sim, the director of Universities Scotland, is due to give evidence to MSPs as the committee considers the SNP administration's budget plans for 2012-23.