ICM poll finds 40% of people would support hydraulic fracturing in their local area and 40% would oppose it

The site in west Sussex that has become the intense focus of the UK's fracking protests may never become a site of fossil fuel production, the company involved admitted on Tuesday night.

Cuadrilla, which has a licence to explore for oil in Balcombe, where 200 local people and large numbers of activists have protested against possible fracking, told the Guardian that other sites nearby were likely to be more suitable.

A spokesman said the company would look for other locations that shared the underlying geology but were further from human habitation. The company as yet has no such sites in mind, nor permission for further drilling.

Cuadrilla's admission comes after more than a fortnight's protests at the Balcombe site, which have attracted international attention. A Guardian poll reveals that fracking has split the electorate down the middle.

Four in 10 people would welcome hydraulic fracturing – used to extract hard-to-reach natural gas – in their area but as many would oppose it, a national ICM survey commissioned by the Guardian has found. About a fifth of voters are undecided.

Worryingly for David Cameron, the research suggests undecided voters could harden against fracking if it is planned for their community.

When asked if it should take place in the UK, a near-majority – 44% of respondents – say yes, with 30% saying no and 26% undecided. But when the question is whether fracking should be allowed near their homes, the number opposed rises to 40%, with those in favour falling slightly to 40%.

The poll also suggests Nick Clegg may find the issue tricky. A substantial proportion, 37%, of Liberal Democrat voters would oppose fracking in their area, while 27% would oppose it nationally. The Lib Dems are particularly exposed on this issue as responsibility for it falls to one of their cabinet ministers, Ed Davey.

Leila Deen, energy campaigner at Greenpeace, said: "The government has done a terrible job of selling fracking to the British public – even with the broad support of the mainstream press it hasn't been able to get a public mandate. Contrast this with recent polling showing 68% support for onshore wind and that 67% of people would prefer a turbine to a fracking site near their home."

Proposals by Cuadrilla, the UK's main fracking company, to operate in Balcombe, West Sussex, have led to protests, with 200 local people and a large number of activists turning up to the site.

"What we've seen in the south is that the more people learn about fracking, the more they have objections," said Deen. "You only need look at what happened with the Balcombe parish council, which approved drilling before understanding the implications. Now they know what it entails, they say they're gutted to have given it the green light. The public's response is liable to be the same."

Andrew Pendleton, head of campaigns at Friends of the Earth, said: "Despite all the hype about fracking, this poll shows government and industry have failed to convince most people to support it. People are being seduced by claims of cheaper fuel bills, but there's plenty of expert evidence to show [it] won't deliver this."

Industry experts, including companies such as BP, have cast doubt on whether fracking on a large scale could take place in densely populated Britain, in contrast to the US, where it is widespread. Cuadrilla has so far spent £100m on a handful of sites since 2010, with no gas yet produced.

The poll results suggest Cameron could face a battle to win over voters in marginal seats to his energy plans – particularly when it comes to women, floating voters and first-time voters.

Women tend to be much less in favour of fracking than men – nationally, 55% of men support fracking but only 34% of women.

More than a third of people aged 18-24 oppose fracking, compared with a quarter of over-65s. Young people also tend to know more about it – only 19% were undecided, compared with 28% of pensioners.

Among Tory voters, Cameron's fracking plans enjoy clear support, with 58% in favour nationally and only 23% against. Opposition hardened when voters were asked about fracking in their area. Only 54% would support such plans, with the number against rising to 31%.

Flaring - when excess gas is burned off at the top if thin chimneys for safety - is likely to take place in many fracking areas, fracking specialists have warned, but is unlikely to be popular. The practice, which adds to the greenhouse gas emissions from the wells, is now so widespread in the US that it can be seen from space at night.

The prime minister this week made his first major intervention in the fracking dispute, which has given rise to protests in Sussex and the north-west and is dividing MPs, communities and business interests.

His enthusiasm for fracking has been matched by his ministers, with George Osborne promising tax breaks for companies and benefits for communities. Michael Fallon, energy minister, signalled his willingness to fight when he declared in a recent private meeting that middle England would have to put up with the impact, saying: "We're going to see how thick their rectory walls are … and whether they like the flaring at the end of the drive."

Fracking is the process by which dense shale rocks are blasted with a high-pressure mix of water, sand and chemicals to release tiny bubbles of natural gas trapped within. In the US, where it was pioneered, the technique has been associated with leaks of methane, air and water pollution, and the overuse of water supplies that has left some areas drying up.

Its proponents in Britain say the tighter regulations in force here would prevent such problems. Ministers have also promised cash and other incentives for communities that accept a fracking operation in their area.