Peter Marki-Zay has emerged as the first serious opposition challenger to Hungary's nationalist Prime Minister Viktor Orban since 2006.

The 49-year-old conservative father of seven is an independent, untainted by association with the pre-2010 Socialist-Liberal coalition defeated by Mr Orban. Nor is he linked to any of the mainstream parties established since the fall of communism in 1989.

As mayor of the central Hungarian town of Hodmezovasarhely since 2018 he has managed to get experience of running an administration, and has quietly built a nationwide following and a strong network of activists. They are called the Movement for a Hungary of Everyone (or MMM - the Hungarian acronym).

One strength is that, as a former marketing manager for a multinational company, who has lived in the US and speaks several languages, he speaks in soundbites.

One weakness is that he has little experience of working with political parties. Yet as prime ministerial candidate of a six-party opposition alliance, he will have to work very closely with them.

Since his landslide victory in 2010, Viktor Orban has reshaped the political and institutional landscape in Hungary in his own image.

His Fidesz party dominates the country's key institutions, in the run-up to the April 2022 general election.

"Perhaps a third of the Hungarian population support Fidesz, another third support the opposition, but Peter Marki-Zay has the ability to appeal both to the opposition and to the missing third - those who do not normally vote, or who are disillusioned with Fidesz," Peter Akos Bod, former governor of the Hungarian National Bank, told the BBC.

Mr Marki-Zay often cites his home town as a microcosm of Hungary.

"The people who ran for office in Hodmezovasarhely were those who would not steal from the public purse, but work for the common good!" he said in a speech a year ago.

The anti-Fidesz centre-right nodded sagely - former government ministers, reporters, theologians and politicians, who have felt homeless since Viktor Orban moved Fidesz to the far right.

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Ironically, Mr Orban's strength today is working to the opposition's advantage.

"Marki-Zay inherits a forced fraternity of parties of different tendencies for the first time in at least a century," said Peter Akos Bod.

"Viktor Orban was kind enough to force us to work together. So in that sense the opposition will be much better prepared to take over than in 1990."

Opposition-minded thinktanks and working groups have been drawing up a new government programme, from healthcare to education to pensions. That will now underpin Peter Marki-Zay's challenge.

The opposition alliance agree that the 2011 constitution, drawn up by Fidesz alone, as well as the many "cardinal" laws pushed through by Fidesz with a two-thirds majority, will have to be overturned. The question is, how that can be done, if they do not enjoy the necessary two-thirds majority?

Mr Marki-Zay favours assembling a team of constitutional lawyers to work on that question.