New opinion polls indicated Scotland could narrowly reject independence as the rival campaigns battled into Wednesday, the final day before a historic vote that could split the United Kingdom.

Three polls released late Tuesday all showed the pro-independence side had gained ground in the final weeks of the debate, but that the “No” campaign was still ahead by a slim margin.

The rival camps were set to fight until the last moment for victory in Thursday’s referendum, with the Better Together and Yes Scotland campaigns both planning rallies of supporters in central Glasgow on the eve of the vote.

Alex Salmond: Yes Campaigner

In a letter to the people of Scotland, first minister and leader of the pro-independence Scottish National Party (SNP) Alex Salmond urged the electorate to take its historic chance to end the 307-year-old union.

“The talking is nearly done. The campaigns will have had their say. What’s left is just us – the people who live and work here. The only people with a vote. The people who matter,” Salmond wrote.

“Wake up on Friday morning to the first day of a better country. Wake up knowing you did this – you made it happen.”

“It’s about taking your country’s future into your hands. Don’t let this opportunity slip through our fingers. Don’t let them tell us we can’t. Let’s do this.”

– Narrowing gap –

All three polls showed that support for independence had increased, but that when undecided voters were excluded, independence was set to be rejected by 52 percent to 48 percent.

The ICM poll for The Scotsman newspaper said “No” support was ahead on 45 percent to 41 percent, with 14 percent of voters still undecided.

Opinium said 49 percent of respondents to their survey of 1,156 backed staying in the union, with 45 percent set to vote for independence and 6 percent undecided.

Meanwhile, a Survation poll for the Scottish Daily Mail said 47.7 percent would vote “No” to independence, and 44.1 percent would vote “Yes”, with 8.3 percent chosing “don’t know”.

An average of polls taken in the final week before the vote puts the race neck and neck, with “No” on 51 percent and “Yes” on 49 percent, according to research institute ScotCen.

“These polls – like all the recent polls – show that we are in touching distance of success on Thursday,” said pro-independence Yes Scotland chief executive Blair Jenkins.

Record numbers of voters have registered for the referendum and turnout is expected to be very high.

Pro-union Better Together campaign director Blair McDougall said there would be no going back from the decision.

“This vote will go right down to the wire,” McDougall said.