Analysis carried out by the party indicated long-term sickness could cost the economy £18.3bn over the next Parliament.
Liberal Democrat Leader Ed Davey said: ‘Rishi Sunak's failure to cut NHS waiting lists is damaging the economy and blowing a hole in the public finances. Years of Conservative chaos have left us with a sick economy and a health service on its knees.'
The Liberal Democrats are calling for the introduction of regular mental health check-ups at key points in people's lives when they are most vulnerable, to help tackle the root causes of the mental health crisis. This would include new parents, children and young people, men in their 40s, carers and retirees, all of whom are at high risk of mental ill health.
The party would also boost funding for NHS talking therapies, making them available to an additional 100,000 people over the next Parliament. The plan would see an additional £70m a year invested in Talking Therapies by 2028-29, funded through a clampdown on tax evasion.
Figures published by the party show 2.8m people were out of work due to ill health in February 2024, up around 700,000 compared to the start of this Parliament in 2019, resulting in an annual loss of almost £3.7bn revenue.