Public concern over the NHS has risen sharply in the last month to its highest level in 15 years, according to an Ipsos Mori poll.

The health service was cited by six in ten people as one of the most important issues facing Britain today – up to 61 per cent in May from the previous month’s result of 48 per cent.

The findings echo a recent poll for The Independent that indicated three in four people believe the NHS is in a bad condition, with 51 per cent of people saying the Tories bear the most responsibility for the current problems facing the NHS.

Concern about the NHS has hit its highest recorded level since April 2002, according to the Ipsos Mori and Economist Issues Index.

"The warnings around inadequate NHS funding have been growing in number and volume over the past few years and now seem to be cutting through with the public in a significant way," said Dan Wellings, senior policy fellow at health charity The King’s Fund.

“This is the fifth highest level of concern recorded since 1997 and the highest it has been since April 2002, prior to Gordon Brown announcing £40bn of extra funding for the NHS,” he wrote in a blog post commenting on the poll.

Audience member during May's comments on NHS: 'Bollocks, absolute bollocks'

Brexit, the Conservatives’ main campaign issue, was mentioned as a concern by 45 per cent of people, while 27 per cent cited education, 25 per cent said immigration, and 20 per cent said the economy.

When asked to name the single most important issue facing the UK, as opposed to listing a range of different matters, Brexit came out top. Leaving the EU was picked as the number one issue by 32 per cent of people, followed by the NHS, chosen by 21 per cent.

Polling data was gathered between 5 and 15 May – before the health service IT system was hit by a global cyber attack and last week’s Manchester attack.

But the health service has been the subject of a number of alarming headlines in recent weeks: Nurses have voted overwhelmingly in favour of a strike ballot over low pay; paediatricians have warned of staff shortages so severe a third of specialist children's wards have been forced to close; and last winter was confirmed as the worst on record for A&E delays.

The Conservatives have promised an extra £8bn over the next five years for the NHS in their manifesto.

While some might point out this falls well short of the £350m a week promised by the Leave Campaign, it’s a clear attempt to woo back voters from Labour, who have pledged a real-terms spending increase of £11.6bn by 2022-23, a reduction of one million from waiting lists, and a pay rise for NHS staff.

The Liberal Democrats have said they will raise income tax by 1p to fund a real-terms increase in health spending of £8.5bn in the same time period, according to analysis by health think thank the Nuffield Trust.

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Health experts have called the Conservative manifesto “deeply disappointing”, with the Health Foundation predicting it will create a funding gap of £12bn in the next four years.

“In a Brexit-dominated campaign and with sharply polarised views about the strengths and weaknesses of the main parties, most commentators do not think the NHS will be a decisive factor at the ballot box," said Mr Wellings.