The SNP’s Westminster leader has accused Boris Johnson of a “massive failure of leadership” in accepting Matt Hancock’s resignation rather than sacking him.

Mr Hancock announced his resignation as Health Secretary on Saturday evening after he was caught kissing a close aide in breach of coronavirus restrictions.

Images and video showed him in an embrace with aide Gina Coladangelo last month.

On Saturday evening, Mr Hancock said: “I understand the enormous sacrifices that everybody in this country has made, you have made.

“And those of us who make these rules have got to stick by them and that’s why I’ve got to resign.”

In reply Mr Hancock’s letter on Saturday, the Prime Minister wrote: “You should leave office very proud of what you have achieved – not just in tackling the pandemic, but even before Covid-19 struck us.”

SNP Westminster leader Ian Blackford tweeted: “Massive failure of leadership by @BorisJohnson. Hancock should have been sacked. A fish rots from its head. So does this UK Government. In Scotland of course we will face a choice on our future. We can say goodbye to the chaos and failure of UK leadership and take a step forward.”

Earlier, the SNP warned Mr Johnson “risks jeopardising vital public health measures” by retaining Mr Hancock as Health Secretary.

The party’s Westminster deputy leader Kirsten Oswald said there are “very serious questions” for Mr Hancock and the incident cannot “simply be brushed under the carpet”.

Shadow Scottish secretary Ian Murray also earlier joined those pushing for Mr Hancock to be go, saying if Scottish Conservative leader Douglas Ross “had any backbone” he join the calls.

In a statement on Thursday, Mr Hancock said: “I accept that I breached the social distancing guidance in these circumstances, I have let people down and am very sorry.

“I remain focused on working to get the country out of this pandemic, and would be grateful for privacy for my family on this personal matter.”

A Downing Street spokesman said that day Mr Johnson had accepted Mr Hancock’s apology and “considers the matter closed”.