Boundary changes: polls for Conservatives and Lib Dems
29 January 2013 Last updated at 14:17 GMT
The Conservatives face a 500,000 vote penalty if proposed changes to Parliamentary boundaries are not adopted, said pollster Peter Kellner ahead of Tuesday's vote by MPs.
He also spoke about the Liberal Democrats potentially losing up to 25 seats at the 2015 general election, and the poll rating needed by the Tories for an outright win.
The YouGov pollster was speaking with blogger Iain Dale and Liberal Democrat peer Lord Rennard ahead of the vote to reduce the number of MPs by 50 to 600, and to redraw the electoral map so constituencies would roughly have an equal number of voters.