Trump’s first defence secretary James Mattis among five to express alarm at ‘reckless’ dismissals of top military figures

• US politics live – latest updates

Five former US defence secretaries have demanded congressional hearings on Donald Trump’s firings of several military commanders, including the chair of the joint chiefs of staff, saying it was done for “purely partisan reasons” and weakens national security.

The five – including James Mattis, who served as defence secretary during Trump’s first presidency – wrote in a letter that they were “deeply alarmed” by the dismissals, which they said were “reckless” and unjustified by operational reason.