Scots politicians have united to oppose UK government plans for a referendum on the same day as the Holyrood elections.
The coalition wants to garner public opinion on replacing the first-past-the-post system for UK elections with proportional representation.
But the referendum date on using the alternative vote system clashes with the Scottish elections next May.
Ian Davidson, chairman of the Commons Scottish affairs select committee, said he opposed the timing.
His comments came as the committee visited the Scottish Parliament to gain the views of MSPs in the issue.
Holyrood members are keen to avoid a repeat of the chaos at the last combined parliament and council elections in Scotland when more than 14,000 voters spoiled their ballots.
In light of that 2007 poll, MSPs agreed to stop combining different elections on the same day.
Mr Davidson, Labour MP for Glasgow South West, said: "My personal view is I'm agnostic on AV itself, I could take it or leave it.
"However, I'm opposed completely to the idea that they should be on same day because that seems to me to make a major mistake in terms of the lack of a 'respect agenda'."
Mr Davidson said there was unanimous opposition from MSPs to the referendum date.
Scottish Secretary Michael Moore has argued that holding the AV referendum on the same day would save £17m in taxpayers' cash.