44 MPs want vote referendum moved
Forty four Tory MPs have signed a motion calling for the voting reform referendum to be moved because it clashes with devolved elections.
Welsh MP Glyn Davies, as well as former Welsh Secretary John Redwood and Sir Malcolm Rifkind are among those to have signed the motion.
The MPs say referendums on big issues should be held separately from elections.
It would allow other issues to "cloud the referendum debate", they say.
The Early Day Motion (EDM), lodged by Harwich and Essex North MP Bernard Jenkin, says the clash would "artificially inflate turnout in some parts of the country but not others, and that it may accordingly advantage one campaign at the expense of the other".
"It may accordingly advantage one campaign at the expense of the other," the motion said.
The Welsh assembly election is due to be held on 5 May 2011, with a date also due to be set for a proposed referendum on more assembly powers.
Glyn Davies, MP for Montgomeryshire, said: "The national assembly elections are the Welsh general elections. It is of such significance that it ought not be interfered with."
Mr Davies said it was a "constitutional matter" and that he remained in favour of the referendum taking place.
The EDM notes that in 2002 the Electoral Commission issued a statement saying that referendums on "fundamental issues of national importance" should be considered in isolation.
Its view followed consultations on the holding of a possible referendum on the Euro on the same day as other elections in May 2003.
EDMs are formal motions submitted for debate in the House of Commons. However, very few EDMs are actually debated.
Instead, they are used for publicising the views of individual MPs, drawing attention to specific events or campaigns, and demonstrating the extent of parliamentary support for a particular cause or point of view.
Deputy Prime Minister Nick Clegg has said an estimated £17m would be saved if the referendum was held on the same day as devolved elections.
However, Mr Davies said: "If we do not like the costs we should not hold them."