Scientists strike at Royal Preston and Chorley hospitals
More than 30 biomedical scientists at Royal Preston and Chorley hospitals have been "forced" to strike, the union representing staff claims.
Scientists at the hospitals started a 24-hour strike over pay and working conditions at 08:00 BST.
Lancashire Teaching Hospitals NHS Foundation Trust said it was "extremely disappointed" over the move.
Unite union's Steve Davies said it was staff who instructed the union to ballot for industrial action.
'Ensure patient safety'
Mr Davies said the trust had imposed working conditions on staff which meant workers could be called into work at a moment's notice and without sufficient cover.
He said: "Home and work-life balance is just appalling.
"It is not often that you hear of scientists going on strike, it is very rare, but they are so fed up and totally distraught it has forced them to go on strike."
He added: "They have had enough. It was them that instructed the trade union, not the other way round, to ballot for industrial action."
Biomedical scientists carry out tests on tissue samples and fluids to help diagnose diseases such as diabetes and cancer, and evaluate the effectiveness of treatments.
Karen Swindley, workforce and education director for Lancashire Teaching Hospitals NHS Foundation Trust, said staff have not had to work excess hours.
She said: "We have increased the number of posts within the service and whilst the recruitment process is on-going we are using additional agency staff to maintain safe service delivery and ensure all rotas can be adequately covered.
"Some staff have volunteered to work overtime for which they have been paid at the usual enhanced rate."
She added cover for scientists was in place to "ensure patient safety is in no way compromised" during the strike.