“This is me right now heading back into the Covid ICU I’ve worked for the last two months,” the doctor said in a tweet.
“Haven’t seen my parents since January,” the doctor, who is also the joint chief executive of HEROES – a charity protecting frontline workers – added.
“Frankly, Cummings spits in the face of all our efforts, the whole #NHS,” he said. ”If he doesn’t resign, I will.”
Mr Cummings, who is the chief advisor to the UK prime minister, has been accused of making two trips to County Durham, where his family lives, despite social restrictions over coronavirus.
Boris Johnson has stood firmly behind Mr Cummings, announcing on Sunday evening at the daily coronavirus briefing that his senior aide had “acted with integrity” and was not going to stand down, despite an increasing volume of calls from Tory MPs for him to do just that.
The 48-year-old has denied returning to Durham in April, weeks after his initial time spent self-isolating in the region.
Speaking outside his London home on Sunday, after one journalist asked if he had been back to Durham in April, he said: “No, I did not.”
Additional reporting by Press Association