Senior Conservative party members are calling for Westminster to restrict the voting rights of Scottish MPs over England-only legislation if Scotland votes against independence on Thursday.

Lord Kenneth Baker, the former Tory cabinet minister, said he believed a no vote would make it inevitable that the voting rights of Scottish MPs in the Commons would be reduced to ensure they could not vote on England-only legislation and tax matters.

He said promises by the UK parties to give the Scottish parliament much greater autonomy over income tax rates and other minor taxes raised big problems for the House of Commons, since it would leave Scottish MPs able to vote on income tax rates in England when English MPs could not vote on those taxes in Scotland.

"A yes vote would be a disaster for Scotland, but a no vote would be a nightmare for England," the former home secretary said.

The Guardian disclosed in June that the UK government's plans to limit Scottish MPs' voting rights, by giving English MPs greater influence at key stages during the passage of legislation, had been dropped until after the general election in 2015.

Liberal Democrat and Conservative coalition ministers could not agree on whether restricting their rights was fair; Lib Dem ministers said cutting any MP's voting rights would undermine the constitutional integrity of Westminster. They also feared this would alienate Scottish voters during the referendum campaign.

Senior Lib Dems and the Labour party leader, Ed Miliband, argue that the most constructive answer to the West Lothian question – whereby Scottish, Welsh and Northern Irish MPs can vote on solely English policies, such as health or schools, while English MPs cannot vote on those areas in devolved legislatures – is to spread devolution within the UK by increasing economic and political powers for England's largest cities and regions.

Meanwhile, a UK-wide opinion poll for ITV's Good Morning Britain found a majority of voters wanted Scotland to vote no, with 53% saying they did not want Scotland to become independent and 21% saying they did. However, nearly half of the 5,000 voters polled by One Poll said they did not care if Scotland became independent.

Baker backed up calls from John Redwood, the Conservative MP for Wokingham, for action on the West Lothian question. Redwood, the former secretary of state for Wales, said over the weekend that he believed an English parliament was the best answer to the West Lothian question – a policy repeatedly rejected by the Conservative leadership as too radical.

"England this time will not be fobbed off with third-class devolution or no devolution at all," Redwood wrote on his blog. "The Scottish vote and attitudes changes things fundamentally – for England as well as for Scotland."

Baker said that giving the Scottish parliament greater tax powers would make the UK's political structures more imbalanced, and would increase pressure from Wales for more autonomy. That question would come up immediately on Friday if Scotland rejected independence.

He said he thought the former prime minister Gordon Brown was correct to suggest the UK could reorganise itself into a more federal structure, under which Westminster acted more as an English parliament when necessary.

"This is an unravelling of the UK but it can be held together still by a federal solution," Baker told BBC Radio Scotland. "It would be totally unfair for [Scottish MPs] to vote on domestic English issues when they can't vote on their own domestic issues in their own country. It's a bizarre relationship, so the West Lothian question will have to be resolved."

One of Scotland's most senior devolution campaigners, the investment banker Ben Thomson, said he was still not convinced that the UK parties' plans for extra powers for Holyrood went far enough, and he was considering voting for independence.

Thomson, who is chair of the National Galleries of Scotland and set up and runs the Devo Plus campaign, said he needed more convincing before he would vote no to independence.

"What I want is something in the middle – a Devo Plus. That is what the public in Scotland, the majority, want. I've said whichever side gets closest to Devo Plus or proper federalism is where I will put my vote," he told BBC Good Morning Scotland.

"I'm waiting to see what will really happen, and if they [Better Together parties] can convince me they will deliver much greater powers after the referendum and a no vote."

• This article was amended on 15 September 2014 to correct an error introduced in the editing stage which said senior Tories wanted to restrict Scottish MPs' voting rights over England-only legislation in the event of a yes vote, rather than a no vote.