More than six out of 10 voters in England and Wales want Scotland to stay in the United Kingdom, according to an Opinium/Observer poll on attitudes towards independence.

The findings suggest that English and Welsh people, as well as the three main Westminster parties, will be exerting pressure on the Scots to vote no in the runup to September's referendum.

Some 61% of the English and Welsh say they want the Scots to stay in the UK, while just 22% say they would prefer them to go their own way as an independent nation.

Support for independence is far higher among men than women in England and Wales, with 29% of men in favour against 16% of women.

Voters aged over 55 are far more likely to want the Scots to stay, with 73% backing them remaining in the union, against just 51% of 18 to 34s.

A majority of UK voters (52%) think Scotland will vote to stay in the UK, while 29% think it will opt to leave.

Almost half of the respondents (46%) backed the view of the three main Westminster partiesthat Scotland should not be able to retain sterling as its currency after independence, while 31% thought it should be able to do so.

In a blow to SNP leader Alex Salmond there was also strong support for the view that Scotland should have to apply to become a member of the European Union after declaring independence, rather than being able to negotiate to stay in while it is still a part of the UK.

On Westminster politics, the poll shows Labour's lead over the Conservatives has dropped to 5% (down four points on a fortnight ago). Labour is on 34%, the Conservatives 29% (up one point), Ukip is on 19% (up two points) and the Liberal Democrats are on 10% (up two points).

Leader approval ratings Photograph: Observer Graphics

Ukip's strong showing, with less than three months to go until the European elections, will alarm the other three Westminster parties. The poll shows Nigel Farage's party with almost twice as much support as the Liberal Democrats, as Farage and Clegg prepare for a "showdown" debate on whether the UK should remain in the EU.

While Ed Miliband's personal ratings have remained steady over the last two weeks (dropping just one point to -17%), those of David Cameron have improved by 4pts to -10%. Nick Clegg's have declined in the last fortnight from -42% to -44%.

Opinium Research carried out an online survey of 1,946 GB adults aged 18+ from 25-28 February 2014. Results have been weighted to nationally representative criteria. Full tables and results available online

• This page was updated on 3 March 2014 to correct a mistake in the spelling of "independence" on the infographic.