Of course Cummings SHOULD resign, but he won't

[Denzil_DC]

3. New eyewitness reports have blown the defence that Cummings

was trying to ensure childcare continued while he and his wife were ill:

New witnesses cast doubt on Dominic Cummings’s lockdown claims

...
The new testimony suggests Cummings left the home where he was staying in Durham to visit a town 30 miles away. He was allegedly spotted back in Durham on 19 April, days after he was photographed in London having recovered from the virus.
...
Ministers insisted he had stayed put once arriving at a property in Durham, where he had travelled after contracting the symptoms of coronavirus to seek the support from his extended family.
...
The two new witnesses were revealed in a joint investigation by the Guardian/Observer and the Sunday Mirror.

One saw him in Durham on 19 April, days after Cummings was photographed in London having recovered from the virus.

A week earlier Cummings was seen by another witness in Barnard Castle on Easter Day, 30 miles away from Durham, the investigation found. The town, which takes its name from the English Heritage site at its centre, is a popular destination for days out.

https://www.theguardian.com/politics/2020/may/23/new-witnesses-cast-doubt-on-dominic-cummingss-lockdown-claims

I'd say, as with the other recent cases of resignations for similar breaches, whether Cummings keeeps his job depends on how long new revelations contradicting the original story versions keep coming out.

Johnson has reportedly already expressed his "full confidence" in Cummings, so it's not looking good for him at the moment.