Crown Princess Catharina-Amalia, 17, has not made any comments on the matter, and little is known of her personal life. The question arose after recently published books argued that the country's rules exclude the possibility of a same-sex royal couple.

But Prime Minister Mark Rutte said times have changed since one of his predecessors last addressed the issue in the year 2000.

"The government believes that the heir can also marry a person of the same sex," Rutte wrote in a letter to Parliament.

"The cabinet therefore does not see that an heir to the throne or the King should abdicate if he/she would like to marry a partner of the same sex."

Gay marriage was legalized in the Netherlands in 2001.

Rutte said that one issue remains unresolved: how a gay marriage would affect later succession of the royal couple's children. And it doesn't make sense to try to decide that now, he said.

"It's just very dependent on the facts and circumstances of the specific case, as you can see by looking back at how family law can change over time," he wrote.

Unlike regular marriages, royal marriages need the approval of Parliament. Members of the Dutch royal house have on occasion given up their place in the line of succession to marry someone without permission.