"He is boarding the plane now," Soumaya Ghannouchi told AFP by telephone from a departure gate at London Gatwick Airport.
Ghannouchi`s British Airways flight to Tunis was due to depart at 0830 GMT and arrive at 1125 GMT.
Following the ousting of authoritarian ruler Zine El Abidine Ben Ali, Ghannouchi checked in at Gatwick to return to Tunisia after 22 years in exile, accompanied by 30 supporters and journalists.
Wearing an open-necked shirt and overcoat, a smiling Ghannouchi posed with the Tunisian flag and embraced relatives.
"I feel very happy today," the 69-year-old said.
"When I return home today I am returning to the Arab world as a whole.
"I am still the leader of my party. I want to organise a conference.
"If there are free and fair elections Ennahda will take part -- in the legislative elections, not the presidential elections."
He added: "There is still confusion regarding the political situation.
"The interim government is changing its ministers every day, it`s not stable yet and its powers are not clear yet.
"It`s not clear who it is accountable to because the current parliament is still the one-party parliament."
Ghannouchi`s return comes as the new government installed after Ben Ali`s downfall unveiled unprecedented democratic freedoms including lifting media controls, releasing political prisoners and registering banned parties.
The Islamist leader still officially has a life sentence from the old regime hanging over him for plotting against the state but in practice other convicted exiles have been able to return without any hindrance in recent days.
The government has drawn up an amnesty, which still has to go to parliament.
Asked whether he supported Sharia law, Ghannouchi told reporters: "All of these have no place in Tunisia. For many years we have agreed alongside the opposition parties common ground, including approving freedom of conscience,
political pluralism... and we have agreed on a paper on gender equality."
Members of Ghannouchi`s Ennahdha (Awakening) movement, which was banned under Ben Ali, are expected to come to Tunis airport to greet him.
He wants to turn his movement -- which is still officially banned -- into a political party that will contest the country`s first democratic elections.
Tunisia`s law prohibits any political parties based on religious grounds.
Ghannouchi founded Ennahdha in 1981 inspired by Egypt`s Muslim Brotherhood but says it is now more like Turkey`s ruling Justice and Development Party.
Some feminist groups however are worried that Ghannouchi`s return signals a rise in political Islam that could endanger their hard-won rights.
Ghannouchi fled Tunisia shortly after Ben Ali came to power in a bloodless coup in 1987. In elections in 1989, which were heavily falsified, an Islamist-backed coalition still managed to win 17 percent of the vote.
Shortly after that, persecution of leading Islamists began and Ghannouchi fled first to Algeria and then to Britain. Hundreds of Islamist activists who stayed behind were thrown into prison, often on flimsy charges.(*)
Editor: Ruslan Burhani
Copyright © ANTARA 2011