BANGKOK - The sister of Thailand's king has said she is "saddened" by the reaction to her attempted bid to become the country's next prime minister.

Princess Ubolratana was disqualified by the country's Election Commission - who are now also seeking to dissolve the party that nominated her.

Her unprecedented nomination broke with the tradition of the Thai royal family publicly staying out of politics.

King Vajiralongkorn had called her bid "extremely inappropriate".

Posting on her private Instagram account, the princess wrote: "I am sad that the sincere intention to work for the country and us Thais has created a problem that shouldn't happen in this day and age."

The photo she posted - of a scenic garden - also included the hashtag #HowComeItsTheWayItIs.

The announcement that Princess Ubolratana would stand for election sent shockwaves through Thai politics last Friday.

The US-educated Thai princess relinquished her royal title when she married an American man in 1972.

She returned to Thailand in 2001 after they divorced and has maintained a quasi-celebrity status since - appearing on the entertainment circuit and in music videos.

She was nominated as a candidate for the upcoming general election by Thai Raksa Chart last week - a party allied to divisive former prime minister Thaksin Shinawatra.

The March vote will be the first since the current Prime Minister, Prayuth Chan-ocha, took power in a 2014 military coup - overthrowing the democratically-elected government.

The royal family and electoral officials condemned her candidacy almost immediately after it was announced.

The country's election panel said it had excluded Princess Ubolratana because "every member of the royal family comes within the application of the same rule requiring the monarch to be above politics and to be politically neutral".(FA)