The medical director of the NHS has promised action after it was reported that hundreds of thousands of patients were being sent home from hospital in the middle of the night to relieve pressure on beds.
Some 3.5% of all hospital discharges took place between 11pm and 6am, a rate that has held steady for the last five years, according to The Times.
The newspaper submitted Freedom of Information requests to all 170 NHS hospital trusts in England, asking for details of patients discharged between those hours.
Some 100 trusts responded, saying that 239,233 patients had been sent home at that time last year.
If all other trusts were discharging at similar rates, this would add up to 400,000 such discharges every year, almost 8,000 a week.
Rates varied between 8.7% and less than 1% across the trusts, the newspaper said.
It quoted patient campaigners saying that the elderly were often worst affected as they are abruptly sent home to empty houses without proper planning.
Sir Bruce Keogh, medical director of the NHS, said: "I am concerned to hear that some patients may be being discharged unnecessarily late.
"Patients should only be discharged when it's clinically appropriate, safe and convenient for them and their families.
"It is simply not fair to be sending people home late at night. We will look at this."