By Marton Dunai and Sandor Peto

BUDAPEST (Reuters) - Hungarian President Pal Schmitt resisted pressure on Friday to quit, saying there was no link between a plagiarism row that cost him his doctorate and his role as head of state, pledging to defend his reputation by writing a new thesis.

The controversy comes at a sensitive time for Hungary as it tries to resolve a lengthy dispute with the European Union on contested new laws to unlock stalled talks on financial support.

The 69-year-old Schmitt, an ally of Prime Minister Viktor Orban, was stripped of his doctorate on Thursday after a months-long plagiarism row that critics say damaged the integrity of his office and drew calls for his resignation.

But Schmitt, a two-time Olympic gold medal-winning fencer who cancelled all of his earlier appearances for Friday, said in an evening interview with public television that there was no reason for him to go.

"These issues are not related in my view, even though many interpret it this way," Schmitt said when asked whether he had considered resigning over the plagiarism scandal.

Opposition parties say cheating makes him unworthy of the job. The main right-leaning daily Magyar Nemzet and influential conservative intellectuals have also called for him to quit.

Schmitt has denied wrongdoing since business news portal hvg.hu broke allegations in January that he had copied large parts of his 1992 thesis from other authors without proper quotes or referencing.

After conducting its own inquiry into the allegations, Semmelweis University stripped Schmitt of his title, saying his thesis did not meet scientific and ethical standards.

But Schmitt has said his conscience was clear, taking issue with the swift decision by the university.

"For them to strip me of my doctorate, so be it," Schmitt said. "I have never gained any financial or moral advantage from it."

"However, I will prove that I still have the perseverance, just as when I was Olympic champion, and even at the age of 70 I will prove that I am able to write a so-called PhD thesis that meets today's very tough standards," he said.

Earlier local media cited unnamed politicians of the ruling Fidesz party and their Christian Democrat allies as saying Schmitt could announce his departure on Friday as his position was growing "more untenable by the hour."

DISHONOUR

Gabor Vago, a lawmaker of the small opposition LMP party, told 150 supporters camped outside Schmitt's palace to demand his resignation: "The gravest problem and dishonor that the president has caused by not resigning is that we can no longer look at politicians and the political elite as an example".

The main opposition Socialist party slammed Schmitt for failing to make what it called "the only morally acceptable decision" and resign, calling on Orban to oust the president.

Under Hungarian law, Schmitt, the least popular president since the collapse of communism, can be removed by a two-thirds majority vote in parliament.

Orban told public radio the decision was in Schmitt's hands.

"I reiterate, this decision is for him to make on his own".

Schmitt has played an instrumental role in pushing the agenda of his ally Orban, signing disputed reforms, such as retroactive taxes, into law.

The decision to withdraw Schmitt's doctorate is also an embarrassment for Orban, who called Schmitt the most suitable candidate for president before his appointment by parliament for a five-year term in 2010.