An NHS doctor has urged people to wear a face mask when they go shopping and has debunked a myth as "medically false".

Dr Joshua Wolrich hit back at claims that wearing a face covering affected a person's oxygen level and told people to "stop making stuff up".

He tweeted a video with the caption: "Masks do not reduce oxygen saturation.

"This is a lie made up as an excuse by those who believe the pandemic is a hoax and that wearing a mask somehow encroaches on their rights."

Speaking to camera the surgeon said he was making a public service announcement about mask wearing and oxygen saturation.

The surgeon donned his mask for the demonstration

He told people that anything between 94 and 100 was a normal level, and he has no respiratory conditions, his level sits at around 99%.

Explaining the numbers of the machine he was hooked up to he said: "The bottom number is my heart rate, anything over 100[bpm] is too fast and mine is fast because I'm p***ed off that I'm having to record this video."

He then put his mask on and the numbers stay the same.

He added: "Masks do not have the ability to reduce your oxygen. That is medically false.

"Stop making stuff up, stop listening to people who are making stuff up and stop turning this into a political issue.

He said he was p***ed off he was having to make this video

"Mask protect you and protect others, if you are told to wear them, do so. Sop being selfish."

He was later criticised for not keeping the mask on long enough so shared a second video of his oxygen level having worn his mask for two hours since his last break,

He added: "Still no hypoxia."

It will become mandatory for shoppers to wear face coverings from Friday, July 24 in England and already is compulsory in Scotland.