The number of patients forced to wait more than 18 weeks for NHS treatment has risen slightly, according to new figures.

Data for England shows 247,423 people in July had not been treated within this time-frame.

This is up on last year when the number for the same month stood at 243,205.

While the total number of people experiencing longer waits has been rising across the NHS since the coalition came into power, average waiting times have shown small signs of improvement.

This year’s outpatient figure stands at 3.9 weeks, compared with 4.3 weeks last year.

For those admitted for care, the results also appeared better - falling from 8.3 weeks to 8.2 weeks, according to the statistics released by the Department of Health.

The majority of people - 90.6% of admitted patients and 97.4% of outpatients - started treatment in 18 weeks or less, meaning the government met its target for 90% of patients to be seen within this period.

But the figures were down on last year which saw 93.3% of inpatients receiving care within the designated time and 98.1% of outpatients.

The NHS Constitution gives patients a right to be seen within 18 weeks of referral by their GP.

The government insists waiting times are stable.

Health minister Simon Burns said: “Average waiting times are low and remain stable. The vast majority of patients still receive treatment within 18 weeks.

“We are committed to driving improvements in performance and the quality of care that the NHS provides - including keeping waiting times low.”

A Department of Health spokesman said: “We have made it absolutely clear that patients should be treated as quickly as possible and within 18 weeks where clinically appropriate.

“In July 2011, the NHS treated more people who had waited longer than 18 weeks than in July 2010.

“Over 90% of all patients are treated within 18 weeks. The average waiting times remain stable at 8.2 weeks for inpatients and 3.9 weeks for outpatients.”

The NHS aims for 90% of inpatients to be treated within 18 weeks and 95% of outpatients.