Alex Salmond has invited Gordon Brown and Alistair Darling to join his "Team Scotland" group to negotiate the breakup of Great Britain if the yes side prevails in Thursday's independence referendum.

As a series of new polls confirmed that the referendum remains on a knife-edge – with the no vote narrowly ahead – the Scottish first minister outlined a three-point negotiating plan that would kick in on Friday after a yes vote.

This includes drafting in a team of specialists to negotiate Scotland's secession from the UK, drawing in leaders of civic Scotland to feed into the negotiations, and ensuring that all political opinions are represented to "bring the country together".

Salmond's remarks prompted Darling, the leader of the pro-UK Better Together campaign, to accuse the first minister of embarking on a "premature victory lap".

Salmond, who said he would declare victory even if he won by just one vote, suggested that another referendum could not be held in this political generation if voters rejected independence. He indicated a timeframe of 18 years but suggested that Scotland would eventually achieve independence as he described no voters as "deferred yesses".

Salmond and Darling made their remarks in appearances on BBC1's Andrew Marr Show, which was broadcast from Edinburgh. The leaders of the two rival camps were interviewed separately but then made an awkward appearance together at the end of the programme, where Darling played down Salmond's offer to join "Team Scotland" by saying he was not a good team player.

The latest opinion polls gave a mixed picture. A poll for the Observer by Omnium showed that the no vote was six points ahead, at 53% to no and 47% for yes – one of the largest leads for no recently.

The Sunday Times's Scotland edition featured an internet poll by Panelbase, which gave a two-point lead to no, at 51% to no against 49% yes (excluding don't knows), showing the yes vote two points higher than the last Panelbase poll for the pro-independence campaign Yes Scotland.

On Saturday, the pro-UK campaign Better Together released its own poll by Survation, which put the no vote at 54%, its highest level recently, and the yes vote eight points behind on 46%.

A smaller poll for the Sunday Telegraph from ICM offered an eight-point lead for yes, putting it at 54% over 46% for no, only two days after an ICM telephone poll for the Guardian put the no vote two points ahead, at 51% to 49% yes.

Polling expert Prof John Curtice said the latest polls confirmed that the late surge in support for yes had continued. But with the Sunday Telegraph choosing a smaller sample of 705 Scots surveyed by internet compared with the 1,000 polled by telephone for the Guardian, Curtice urged some caution. On his polling blog What Scotland Thinks, Curtice said that made its findings "more vulnerable to the possibility that its results deviate from the true picture as a result of chance".

Salmond said he was confident of achieving a "substantial majority" but said he did not expect another referendum to be held in this political generation if the no side prevailed. He defined this as 17-18 years – the period between the 1979 referendum on whether to establish a Scottish assembly and the 1997 referendum that led to the establishment of the Scottish parliament.

The Scottish first minister said: "In my view this is a once in a generation, perhaps even a once in a lifetime, opportunity for Scotland."

But Salmond suggested that he was confident that independence would eventually be achieved, even in the event of a no vote, when he said that many no supporters instinctively support him. "There isn't so much as a no vote in Scotland – there are only deferred yesses."

The first minister said he would move quickly after a yes vote to bring Scotland together. "On Friday, after a yes vote, there will cease to be a yes campaign and a no campaign. There will be a Team Scotland. I have said very clearly I want into that Team Scotland as many voices as possible – people who have got something to offer or to contribute to bring the country together."

Asked whether he meant Darling and Brown, the first minister said: "That is exactly who I mean." Alistair Carmichael, the Liberal Democrat Scotland secretary, has indicated that he would resign from the cabinet after a yes vote and join Salmond's team.

Salmond also moved to reassure wavering voters by pledging that he wanted the Queen "and her successors" to serve as monarch in Scotland. He said: "We want to see Her Majesty the Queen as Queen of the Scots. That is a fantastic title and a fantastic prospect."

Darling criticised Salmond for assuming victory. The leader of the Better Together campaign said: "He seemed to be doing a rather premature victory lap even before most of us have voted."

Asked whether capital would flood out of Scotland after a yes vote if there was no agreement on a currency, Darling said: "That is a very real risk."

The former chancellor said Salmond's plan to form a currency union with the remainder of the UK after independence was not realistic. He said: "The real problem is that it is neither in the interests of Scotland to have a currency union because it means your economic policy would be decided in London … And for the rest of the UK they'd have to underwrite our banking system without being able to regulate it."

In their joint appearance at the end of the programme, Darling laughed off Salmond's plan to bring together a cross-party group to negotiate Scotland's secession from the UK. He turned to the first minister and said: "Teamwork Alex, it doesn't always fit naturally with you."