South West MPs say tourists will put unnecessary strain on the NHS amid the coronavirus crisis.
Steve Double, MP for St Austell and Newquay and Anthony Mangnall, MP for Totnes, urged people not to come to the county on holiday.
The Prime Minister has said everyone should avoid "non-essential" travel.
One holiday resort has received death threats for encouraging visitors to self-isolate in flats in Cornwall.
Mr Double said on Facebook: "We have enough to deal with on our own without people coming here with the virus."
Mr Double, Conservative MP for St Austell and Newquay, said: "As a proud Cornishman I never thought I would say this, but please do not come to Cornwall for a holiday in the coming weeks."
He also said in an open letter with Cornwall Council leader Julian German, that "we need to stop the spread of this virus" and "protect our NHS and keep our supermarket shelves stocked".
Conservative MP Mr Mangnall, whose Totnes constituency includes the tourism hotspot of the South Hams, tweeted: "If you have Covid-19 please do not travel across the country to your second homes."
I can’t believe I have to say this but if you have Covid-19 please do not travel across the country to your second homes. You must self isolate & follow the government guide lines.— Anthony Mangnall MP (@AnthonyMangnal1) March 20, 2020
If you travel with the virus you are spreading it. #followtheadvice #selfisolate #think
Jess Earle of Portwrinkle Holidays in south east Cornwall said he had received death threats after offering holiday flats for people to self-isolate.
"The idea is to allow families with elderly relatives to come down here and ride this out at winter rates," he said.
"We are very secluded and we've had a lot of interest.
"But I've had a lot of stick about bringing disease into the country which is very sad.
He added: "This is a national emergency and we should work together.
"I have got staff to pay and I thought we were doing a bit of a service."
Cornwall Council and Visit Cornwall issued a joint statement urging people to come "later in the year".
Malcolm Bell of Visit Cornwall said locals were "very nervous" about an influx of visitors.
"I think we need clarity from the government so that 'non-essential travel' includes a holiday and includes a short break," he said.
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