Earlier, Charles's office had said Camilla would be known as the Duchess of Cornwall after her marriage and intends to take the title Princess Consort when Prince Charles accedes the throne.
Queen rejects Charles marriage plans
But a spokeswoman for the Department for Constitutional confirmed Monday that legislation would be needed for Camilla not automatically become Queen on Charles's succession, no matter what Camilla wished to call herself.
Earlier, accusing Prince Charles of being "less than frank with the country" over his marriage to Camilla, Labor lawmaker Andrew McKinlay said legislation would be needed in 17 parliaments around
"Prince Charles has been less than frank with the country - he knows that it was established in 1936 that the King's spouse automatically becomes Queen unless there is a law passed to the contrary," he told BBC Radio 4.
"I think he [Prince Charles] is deliberately holding this wedding under the smokescreen of a General Election."
Charles denies allegations of tryst with staff
The 56-year-old heir to the throne divorced late Princess Diana in 1996. She died in a automobile accident in Paris the following year.
The Prince, who first met Camilla, 57, at a polo match in Windsor in 1970, has lately her a more prominent public role, frequently taking her to official engagements.
Their wedding was finalised last year after the Church of England said it would not oppose their marriage.
