Complaints about the borough’s hospitals have soared by more than 30 per cent in the past two years.
New data from NHS Digital shows Wrightington, Wigan and Leigh NHS Foundation Trust received 480 new written complaints in 2017-18.
That was a 31.5 per cent rise from 365 complaints in 2015-16 and two per cent increase from 470 last year.
The trust said the rise reflected its “continued approach to be open, honest and transparent” and highlighted the “pressure” faced by the NHS.
The data shows 408 of the complaints were resolved last year, with 406 being upheld and just two not upheld.
All of the resolved complaints in 2016-17 and 2015-16 were upheld.
A trust spokesman said: “The increase in formal complaints to the trust is reflective of our continued approach to be open, honest and transparent as we value and encourage all our service users to provide us with feedback about their experiences, both positive and negative.
“This approach ensures we are listening and learning, keeping the patient at the forefront of everything we do.
“The trust recognises there has been an increase in the number of formal complaints received over the last two years and are aware of not only the pressure on the National Health Service as a whole, but of the local pressures of the services provided here at WWL.
“In real terms, there has been an increase in complaints of 0.08 per cent and 0.07 per cent for 2016-17 and 2017-18 respectively, taking into account the total activity of the trust over the last two years.
“We continue to keep the lines of communication open for patients, relatives and carers to raise concerns and complaints, either via social media or traditional avenues.
“We provide PALS (Patient Advice and Liaison Service) information on our website, in wards and clinic areas, giving people the option to raise their concerns and complaints in a number of different ways.”