Scots are the most satisfied about the way democracy works in the UK, a poll published today shows.

Yet the snapshot of 2000 Britons, taken by YouGov for the Fabian Society earlier this month, also shows that voters north of the border are the strongest advocates when it comes to certain changes.

For example, Scots are most strongly in favour of changing Westminster's voting system to proportional representation; and have by far the firmest republican tendencies, as they are the biggest supporters of replacing the Queen with an elected president as head of state, and are most in favour of having an elected House of Lords.

The survey also shows that a clear majority across Britain, 54%, believe in the wake of the expenses scandal that now is a "once-in-a-generation chance" for a major overhaul of how the nation's constitution works.

The aftermath of the controversy has seen the Commons vote through a num- ber of changes already, such as stopping outer London MPs claiming for second homes, getting MPs to publish all receipts to back up all expense claims, and making public full details of second jobs, which has already begun.

The rush is now on to get on the Statute Book the Parliamentary Standards Bill - which, among other things, sets up the new Independent Parliamentary Standards Authority to oversee MPs' pay and allowances - by tomorrow, when Westminster rises for the summer recess.

In addition, standards watchdog Sir Christopher Kelly is reviewing how the UK Parliament works and is due to report in the autumn.

The YouGov poll asked a number of constitutional questions.

Firstly, how satisfied are people with how democracy works in the UK?

Overall across Britain, 42% said they were satisfied and 50% said they were not.

However, in Scotland, the respective figures were quite different: 56% and 39%. While no reason is given, the fact that Scotland now has its own well-established parliament that concentrates on day-to-day domestic matters such as crime, health and education might have something to do with the sharp difference.

Asked which statement came closest to their view, 54% (49% in Scotland) said this was a once-in-a- lifetime opportunity to overhaul British democracy, while 27% (26%) felt the constitution was tried and tested and care should be taken about changing it too quickly.

Some 52% (48%) felt that a special "citizens' convention" should be established to examine how the UK is governed, while 19% (20%) felt MPs should instead hold a special parliamentary session to come up with a reform package.

Those surveyed were also asked to indicate those they agreed with from two or three options in a list of suggested reforms.

Most, 59% (55%), believed that the Prime Minister should no longer have the power to call a General Election but, rather, there should be fixed terms.

Some 36% (24%) said voters should be able to sack their MP between General Elections; 33% (47%) backed an elected House of Lords; 24% (25%) supported a written constitution while 11% (21%) supported replacing the monarch with an elected head of state.

On voting reform, some 34% (41%) said they favoured PR over the current first-past-the-post system for Westminster, with the Alternative Vote system coming top of the second preferences at 37%(41%).

On general voting intentions, the Conservatives received 39%, Labour 26% and Liberal Democrats 19%. In the Scottish sample the figures were Labour 35%, SNP 30%, Conservative 16% and Lib Dem 13%.

Interestingly, when asked how unlikely people were to change their voting intentions, Scots came out as the most unlikely at 44% compared to a nationwide average of 34%.

Tom Hampson, editorial director of the Fabian Review magazine, which will carry the poll's results in its next edition, said: "There's been a very significant shift in how people now see parliament and MPs.

"The desire for fixed-term elections is particularly interesting because it suggests a desire for more formal structure in the system, even if it's at the expense of the power of our elected representatives."

He added: "There's a growing movement for significant overhaul coming now from many directions - including from campaigning and civil society groups and from government itself - and parliament may find itself unable to resist this."