Keir Starmer has not ruled out the idea of smoking being banned in some outdoor spaces, including pub gardens and outside restaurants, as ministers consider fresh tobacco curbs which hospitality groups say could adversely affect the sector.

It is understood Downing Street is in favour of a series of measures outlined in documents connected to the planned wider tobacco and vapes bill, details of which were seen by the Sun.

The bill would gradually make all smoking illegal by prohibiting the sale of tobacco to people born on or after January 2009, an idea first proposed in the UK by Rishi Sunak’s government, and taken on by Labour.

According to the Sun, it would also impose new restrictions on outdoor smoking, including outdoor spaces at, and pavements outside, clubs and restaurants, as well as at universities, children’s play areas and small parks.

Ministers could target vapers as well as shisha bars, it said. The restrictions would not cover private homes or large open spaces, such as parks, or streets.

Asked about the report during a visit to Paris, Starmer did not deny the plans. “My starting point on this is to remind everybody that over 80,000 people lose their lives every year because of smoking,” he said.

“That is a preventable death, it’s a huge burden on the NHS and, of course, it is a burden on the taxpayer. So, yes, we are going to take decisions in this space, more details will be revealed, but this is a preventable series of deaths and we’ve got to take action to reduce the burden on the NHS and the taxpayer.”

The prime minister added: “It is important to get the balance right, but everybody … who uses the NHS will know that it’s on its knees.”

While precise plans for the curbs are likely to change after consultations, it is understood that ministers are in favour of many of the suggested ideas to limit outdoor smoking.

Last month’s king’s speech, which set out the tobacco and vapes bill, detailed the gradual age ban but made no mention of an outdoor ban.

While health experts backed the proposals, the hospitality industry said it could particularly impact pubs, and anti-smoking groups said it was important to allow some outdoor spaces for smoking, so people did not simply smoke at home, which creates even more adverse health effects.

Dr Layla McCay, the director of policy at the NHS Confederation, said she was “heartened” to see progress being made on abolishing smoking.

She told BBC Radio 4’s Today programme: “It is absolutely the health challenge of our time. It’s the leading cause of preventable illness in the UK, so we are heartened to see that progress is being made and that the intention is moving forward to really address one of Britain’s main drivers of health inequalities.”

Kate Nicholls, the chief executive of UKHospitality, which represents thousands of pubs, restaurants and cafes, said a ban raised the prospect of “serious economic harm” to venues.

“You only have to look back to the significant pub closures we saw after the indoor smoking ban to see the potential impact it could have,” she said. Nicholls called on the government to hold a “detailed conversation” with affected parties on the impact of such a ban before any legislation was put in place.

William Lees-Jones, the head of JW Lees brewery which owns and operates 150 pubs, inns and hotels mainly in north-west England and north Wales, said the idea was a “bolt from the blue” which had not been discussed with industry. He said it would be “really bad for business” and could “shut a lot of pubs”.

“People who smoke are pretty determined and will walk 10 yards down the road and smoke there, which will annoy other people,” he added.

However, Tim Martin, the boss of JD Wetherspoon, said he did not think a ban would have a “big effect” on business: “The question is whether the government should interfere in individual liberties, where danger is involved.”

A spokesperson for the Department of Health and Social Care said: “We do not comment on leaks. Smoking claims 80,000 lives a year, puts huge pressure on our NHS, and costs taxpayers billions. We are determined to protect children and non-smokers from the harms of second-hand smoking. We’re considering a range of measures to finally make Britain smoke-free.”

In 2007, under the Labour government, smoking in enclosed public places and workplaces was made illegal across the UK.

According to the charity Action on Smoking (Ash), in the year after the introduction of smoke-free laws there was a 2.4% reduction in hospital admissions for heart attacks in England, resulting in 12,000 fewer admissions to hospitals, which saved the NHS £8.4m in a year.

In the first year after the introduction of the indoor smoking ban there was a 12.3% reduction in hospital admissions for childhood asthma, equivalent to 6,803 fewer admissions over three years.