Two news polls have shown the 'no' campaign storming ahead in the alternative vote referendum.
In a ComRes poll, No to AV took a 20-point lead among Labour supporters, with 60% of likely voters rejecting a switch to AV.
Meanwhile, a New Statesman/ICD poll found the 'no' campaign were up by 14% among those certain to vote.
In both polls, the 'no' campaign still maintained a significant lead when uncertain voters were included.
A spokesman for No to AV said the campaign would not become "complacent".
"This is the latest in a series of promising polls but there will be no complacency from the campaign for 'one person, one vote'," they said.
"With just over a week to polling day, No to AV activists will be working hard to ensure that people go out and vote on May 5th."
Crucially, the ComRes poll also found that among divided Labour supporters - who could decide the referendum as the Liberal Democrats are united for AV, while the Conservatives want to keep first-past-the-post - 61% would vote against reform.
But the New Statesman found the party's divide was closer, with 47% against AV compared with 41% backing the change.
Siobhain McDonagh MP, patron of Labour No to AV, said the ComRes poll showed Labour supporters hadn't been fooled by "Clegg and his cronies".
"It is great to see that Labour voters are seeing the arguments and coming to their own conclusion that the alternative vote is unfair and expensive and unwanted, she said.
"The senior Lib Dems on the Yes to AV campaign have got increasingly shrill and ridiculous in their attacks on a no vote, but Labour aren't fooled by Clegg and his cronies."
The New Statesman's poll also showed most Lib Dem and Green voters following their leader's recommendations and backing AV, while Conservatives overwhelmingly rejected the voting reform.
But Ukip supporters wanted to keep first-past-the-post despite leader Nigel Farage campaigning for a change to the voting system. And BNP voters, who both sides have claimed back the other campaign, are backing AV even though Nick Griffin supports first-past-the-post.
The magazine's poll found Scottish and Welsh voters were set to reject AV, while Londoners are evenly split.
Both the campaigns for and against the alternative vote have become increasingly negative in the run-up to polling day.
In the latest dispute, the 'no' campaign said a new leaflet from the 'yes' campaign was "disgraceful scaremongering".
The leaflet asks voters: "whose side are you on?", with the remainder of the page divided by a bold black line.
On one side, 'YES' is written next to a box marked with an x, followed by the logos of Labour, the Liberal Democrats, Ukip and the Greens.
On the other side is an empty box with 'NO' written next to it, with logos for the Conservatives and the BNP.
But No to AV accused the 'yes' campaign of "shameful dirty tricks" because the Liberal Democrat logo was much smaller than Labour's or the Conservative's and the party's name had been removed.
The 'no' campaign said it was a misrepresentation to include Labour as pro-AV, when the party is divided, and to include the BNP against the change when its supporters are backing AV.
With the referendum taking place next Thursday, both sides will be campaigning hard during the final week.
The 'no' campaign plans to distribute ten million leaflets and hold hundreds of events.
Meanwhile, AV-supporter comedian Eddie Izzard will be embarking on a whistle stop tour of the UK to promote the 'yes' campaign.
In a four-day period, he will host events in every region of England, along with visiting towns and cities in Northern Ireland, Scotland and Wales - taking in as many as five cities in one day.