Bolton South East MP Yasmin Qureshi has been admitted to hospital with pneumonia after testing positive for Covid-19.
The Labour MP said she started to feel unwell about two weeks ago and immediately self-isolated at home.
Ms Qureshi, 57, said she was admitted to Royal Bolton Hospital on Saturday after beginning to feel "much worse".
"I'm being very well looked after and have nothing but praise and admiration for the wonderful staff," she added.
"They have been amazing throughout the process and I would like to extend my thanks to everyone working here in such difficult circumstances."
Thank you for all the kind wishes. Please see my Facebook page for a statement on my current health.— Yasmin Qureshi MP (@YasminQureshiMP) October 19, 2020
I would like to reiterate my thanks to the hospital staff for the care I am receiving. https://t.co/6HUMKtthtf
Shadow international development minister Ms Qureshi has been one of the Greater Manchester MPs arguing against tier three restrictions being imposed in the region.
Local leaders want better financial support before agreeing to a move to the top tier of rules, which would force some businesses to close.
Greater Manchester mayor Andy Burnham has called on the government to reintroduce the 80% furlough scheme instead of a new Job Support Scheme, which covers 67% of the wages of people affected by tier three closures.
He said businesses that would close under tier three "are places where people are on low wages" and two-thirds pay was not enough.
But Communities Secretary Robert Jenrick has said further delays to a decision will "put people's lives at risk".
Labour leader Keir Starmer has tweeted his support for Ms Qureshi, saying: "My thoughts are with my friend @YasminQureshiMP who has been admitted to hospital after being diagnosed with Covid-19.
"My thanks go to the staff caring for Yasmin at the Royal Bolton Hospital, along with NHS staff across the country who are on the frontline against Covid-19."