51 trusts miss waiting time limits
The number of hospital trusts breaching waiting time limits has more than doubled in a year, figures show.
Data for April shows 51 trusts - around a third of the total - are not hitting the limit for treating patients within 18 weeks of referral by their GP.
This compares with 25 trusts a year ago, the BBC reported.
However, many hospitals are doing better than expected, meaning the NHS is still meeting its pledge of treating 90% of patients within 18 weeks.
Some trusts are hitting far higher than 90%, meaning across England on average, 90.5% of inpatients are seen within this time.
But problems are being experienced in London, the South East, south coast and North West.
In the worst performing area - Hastings and Rother - more than a quarter of patients are waiting longer than 18 weeks.
The issue of waiting times has raised controversy after Health Secretary Andrew Lansley scrapped the 18-week target set by Labour.
However, he said hospitals were still expected to treat patients within 18 weeks as it is part of the NHS Constitution commitment to patients.
Prime Minister David Cameron has also promised to keep waiting times down.