The train derailment in Aberdeenshire which left three people dead resembled a "Hornby set thrown up in the air", the Transport Secretary has said.
Driver Brett McCullough, 45, conductor Donald Dinnie, 58, and passenger Christopher Stuchbury, 62, died on 12 August.
The Aberdeen to Glasgow service hit rocks and gravel washed onto the line after heavy rain.
A rail union official described the remark by Grant Shapps as "glib".
Mr Shapps made the Hornby comparison when the tragedy was raised in the House of Common by Labour as it pressed the government on privatisation and UK suppliers in the rail industry.
Kevin Lindsay, organiser of the rail union Aslef in Scotland, said it was a poor choice of words, describing them as "glib".
He said: "This was a real accident, involving real people - three of whom died, and six of whom were injured - and a real train.
"It was not a Hornby model train set thrown up in the air in a Tory government minister's playroom.
"Mr Shapps really should think more carefully about what he says and how he says it. Because he is treading on the feelings of the families and friends and colleagues of those who died."
An interim report from Network Rail last week said the impact of climate change on its network "is an area that is accelerating faster than our assumptions".
The report also suggested that industry rules for reporting and responding to heavy rainfall should be improved.
Mr Shapps said on Thursday: "I went to the scene of the tragedy. I was taken over in a helicopter. It was like a Hornby train set thrown up in the air.
"Our thoughts and prayers are with, not just the three who died, but those who were injured and the emergency workers and the brave people who rescued them.
"The House will have noticed that I issued the Network Rail interim report on Stonehaven which comes to some very important interim conclusions and I'll update the House further with the full report shortly."
Work involving a 600-tonne lifting crane to remove the carriages has been ongoing.