Tech giants including Google, Facebook and Snapchat will work alongside suicide prevention experts from the Samaritans in a new government-backed project aimed at limiting the impact of harmful online content.

The health secretary, Matt Hancock, will announce the initiative at a roundtable on Monday.

The new scheme forms part of a concerted cross-government effort to rein in the social media companies, amid growing concern over the prevalence of harmful content online across areas including terrorism, child abuse, self-harm and suicide.

In one high-profile recent case, the father of teenager Molly Russell argued that she had killed herself partly because of self-harm images viewed on social media.

Instagram later agreed to remove all graphic images of self-harm.

In the recent online harms white paper, ministers said they would create a new independent watchdog and legislate for a statutory duty of care for social media firms that could see senior executives held personally liable.

But with ministers expecting that it could take many months or even years for the proposals to become law, they are keen to find ways of changing the behaviour of the tech giants in the meantime.

Hancock said the new panel would “see us team up with Samaritans to enable social media companies to go further in achieving our goal of making the UK the safest place to be online”.

It is expected to take evidence from online users with direct experience of mental health issues, suicide and self-harm and ensure the industry’s responses to eradicating harmful content are effective.

Ruth Sutherland, the chief executive of the Samaritans, said: “This partnership marks a collective commitment to learn more about the issues, build knowledge through research and insights from users, and implement changes that can ultimately save lives.”

She added: “There is no black and white solution that protects the public from content on self harm and suicide, as they are such specific and complex issues. That is why we need to work together with tech platforms to identify and remove harmful content while being extremely mindful that sharing certain content can be an important source of support for some.”

Hancock also said he would be urging the social media giants at Monday’s roundtable to take a “zero tolerance” approach to content making false claims about the risks of vaccinating children, after it emerged that measles cases have quadrupled in a year.