A bid by the European parliament to impose an 80% cut in the 100bn plastic bags used by Europeans each year could be scuppered by several states opposed to Europe-wide action, and a European commission that increasingly views targets as an unnecessary distraction.

‘Single use’ plastic bags are light, convenient and easily thrown away but their very disposability creates an environmental threat. As many as a million seabirds and 100,000 sea mammals – including large numbers of seals and turtles – are killed each year by ingesting plastics or becoming entangled in the growing number of plastic islands that gloss large swathes of the world’s oceans.

But several countries led by the UK and Croatia are opposing EU-wide mandatory pricing or product restrictions for plastic bags. France and Spain are more supportive but the commission’s first vice president Frans Timmermans on Wednesday said that he was “not sure” whether the proposal reflected the previous commission’s original intent.

The Guardian has learned that the commission’s secretariat-general is currently discussing whether to reject the proposal in a final negotiating round on Monday, sending it back to a council of EU ministers where it would likely be blocked by the need for unanimity.

“I fear that although the member states agree that we have to act, they do not want us to tackle it at the European level altogether,” said the Dutch Liberal MEP Gerben-Jan Gerbrandy. “It is extremely worrying as this is the fundament of EU environmental legislation.”

“Plastic bags are a huge environmental problem that can be very easily solved, and that doesn’t happen very often anymore in the environmental field,” he added.

The average EU citizen used 191 plastic bags in 2010 and only 6% of them were recycled, according to the commission. But when Ireland introduced mandatory pricing for single-use plastic bags in 2002, their use was reduced by 90% within a year.

British opposition to a bag ban has been derided by Greens in the European parliament who have focused their fire on a strong UK stand against a ban of ‘oxo-degradable’ plastic bags, despite contrary advice from the UK environment department. The Greens suggest the UK’s position is a result of the business affairs of leading Tory politicians and the government’s Eurosceptic impulses.

Symphony Environmental Technologies, the largest manufacturer of oxo-degradable bags, counts the Tory MEP Nirj Deva as chairman of its board, the former Tory MP Michael Stephen as its deputy chairman, and the ex-MEP and chair of the European Conservatives and Reformists group in parliament, Lord Callanan, as its consultant.

Despite only employing 30 people worldwide, the company has succeeded in making use of oxo-degradable bags mandatory in countries such as Pakistan, Iran, Serbia and Kosovo.

But studies by the Department for Food, Environment and Rural Affairs (Defra) and others suggest that the bags take two-five years before degrading, after which their additives help fragment the plastic into micro-plastics, which stay in the environment for many more years and cannot be composted or recycled.

“We are faced with a situation where a Tory government in the UK is fighting hard to defend a very small company with Tory ties, using absurd technology that creates environmental problems and turning the issue into another power struggle between the EU and the UK,” said Margrete Auken, the Green MEP and parliamentary rapporteur on plastic bags.

In Brussels too, facing down the plastic bags proposal and other environmental plans left over from José Manuel Barroso’s term is seen by some as a way of cementing the new commission’s image.

A block on the bags dossier would be in line with a document sent by Timmermans and Jean-Claude Juncker to other commissioners on 7 November, seen by the Guardian, which suggests “withdrawing pending proposals” from the previous administration in a works programme due to be announced on 16 December.

Laws pencilled in “for review” include: a clean air package which would include mandatory curbs on atmospheric pollutants; a waste package with binding recycling targets of up to 80% for 2030, and an energy taxation directive.

Several cross-party MEPs have already reacted with a strong letter to Juncker defending the clean air and waste packages for their “huge potential for jobs and growth, as well as environmental benefits.”

Gerbrandy told the Guardian that talk of burying such key environmental policies was “unacceptable,” and symptomatic of a commission retreat on environmental issues.

“The letter by Juncker and Timmermans is extremely alarming,” he said. “I find it unbelievable that Juncker and his people seem to believe that the environmental agenda is damaging competitiveness and growth. He seems to be trying to revive the last century economy we had in the 1980s instead of looking at the clean economy we’ll need in the coming years. In the future, a company will either be sustainable or it won’t be there at all.”

On Gerbrandy’s initiative, Timmermans has now been invited to explain his thinking at a forthcoming environment committee meeting in parliament.

An EU source told the Guardian that the underlying issue was about the value of legally enforceable action itself. “It is in the air that it’s not good to have targets,” the source said. “There’s an idea that there are too many targets and we shouldn’t have yet another one.”

The single-use plastic bags goal chosen by the European parliament is ambitious – for a 50% reduction within three years, rising to 80% by 2019 – with states retaining the choice to impose mandatory pricing or manufacturing restrictions.

The commission’s impact assessment predicted that this would bring €740m of savings across Europe of per year due to reduced litter collection, easier waste management and increased retail profits.

England plans to introduce a 5p plastic bag charge in October 2015, following similar schemes in Wales and Scotland.

“We are determined to tackle the blight caused by discarded plastic bags, which is why we are introducing a 5p bag charge in England from October 2015,” a UK government spokesperson said. “We are interested in the European commission’s proposals and are engaging constructively.”