The completion of the renovation of the five-red-AA-star, 157-bedroom property on the South Ayrshire coast, which is due to reopen in June 2016, could be delayed if funding is pulled.
The billionaire property tycoon, who also owns Trump International Golf Links near Aberdeen, has issued a statement warning his Trump Organisation would "immediately end" current and future investments if a ban goes ahead.
Trump Organisation said it had planned to invest more than £200m at Turnberry and a further £500m at the Aberdeenshire golf course.
The statement, produced by George Sorial, said: "Any action to restrict travel would force the Trump Organisation to immediately end these and all future investments we are currently contemplating in the United Kingdom."
Later this month MPs will debate whether the US presidential hopeful should be refused entry to the UK, after a petition calling for Trump to be barred has attracted more than 570,000 signatures.
The petition was set up in response to comments made by Trump calling for a temporary ban on Muslims entering the United States.
Trump Organisation's statement continued: "Westminster would create a dangerous precedent and send a terrible message to the world that the United Kingdom opposes free speech and has no interest in attracting inward investment."
The matter of whether to bar Trump from entering the UK will be debated in Westminster Hall on 18 January. There will be no vote at the end of the debate and it will be up to Home Secretary Theresa May to decide whether Trump should be excluded.
A rival petition, which opposes a ban on Trump as illogical has attracted more than 40,000 signatures.
Turnberry Trump is owned and operated by the Trump Organisation under a franchise agreement with Starwood Hotels & Resorts.
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