Thousands of operations have been cancelled because hospital beds are not available, the Liberal Democrats have said.
New figures released by the party show that across 40 NHS organisations in England, 10,259 operations were cancelled last year due to beds not being available.
This represents a 57% increase from 2014 when the figure stood at 6,545, according to freedom of information requests by the party.
Liberal Democrat health spokesman and former health minister Norman Lamb said: "These shocking figures show the impact Conservative underfunding of the NHS is having on hospitals across the country.
"A chronic lack of beds has meant more and more operations being cancelled - often at the last minute - causing huge disruption to patients and their families.
"Tomorrow is a chance to save the NHS as we know it.
"The Liberal Democrats will invest an additional £10 billion in the NHS to fix our run-down hospitals, reduce overcrowding and build a world-class health service.
"This is on top of the £6 billion a year for the NHS we would raise by putting a penny on income tax."