Former Labour home and foreign secretary Jack Straw has criticised a “party political flyer” sent out to two million Scottish households during the independence referendum campaign.
He said the letter “without any question” breached purdah and “probably” the normal rules of public spending too.
He made the comments while giving evidence to the public administration and constitutional affairs committee which was considering the UK Government’s plans to not have a normal purdah period for the referendum on EU membership.
The Government denies breaching purdah, pointing out that the mail drop was before it began, sent on 23 June ahead of the vote on 18 September.
A Scotland Office spokesman said: “It was a very important decision and people needed to be properly informed about what was at stake and the issues behind them.
“It was also a clear government policy to keep Scotland in the UK and we had a duty to clearly explain that to people in Scotland.”