Tunisia's biggest political party assembled tens of thousands of supporters in the capital on Saturday in a show of strength that could fuel a dispute between the president and the prime minister. In one of the biggest demonstrations since Tunisia's 2011 revolution, Ennahda supporters marched through central Tunis chanting "The people want to protect institutions!" and "The people want national unity!". The dispute has played out against a grim backdrop of economic anxiety, disillusionment with the democratic process and competing reform demands from foreign lenders and the UGTT, the powerful main labour union, as debt repayments loom. Ennahda, led by Parliament Speaker Rached Ghannouchi, has backed Prime Minister Hichem Mechichi in a stand-off with President Kais Saied over a cabinet reshuffle. Banned before the revolution, it has been a member of most governing coalitions since then and, although its share of the vote has fallen in recent years, it still holds the most seats in parliament. "Nationalists, Islamists, democrats and communists," Mr Ghannouchi told the crowd, "we were gathered together during the dictatorship ... and we must unite again." The most recent election, in 2019, delivered a fragmented parliament while propelling Mr Saied, an independent, to the presidency. When the government collapsed after only five months in office, Mr Saied nominated Mr Mechichi as prime minister. But they soon fell out, and Mr Mechichi turned for support to the two biggest parties – Ennahda and jailed media mogul Nabil Karoui's Heart of Tunisia. Last month, Mr Mechichi changed 11 ministers in a reshuffle seen as replacing Mr Saied's allies with those of Ennahda and Heart of Tunisia. The president, however, has refused to swear four of them in. Meanwhile, demonstrators protesting last month against inequality and police abuses focused most of their anger on Mr Mechichi and Ennahda. Ennahda billed Saturday's march as "in support of democracy", but it was widely seen as an effort to mobilise popular opposition to Mr Saied, raising the spectre of competing protest movements. "This is a strong message that all the people want dialogue and national unity," Fethi Ayadi, a senior Ennahda official, told Reuters. To add to the tensions, demands by foreign lenders for spending cuts, which could lead to unpopular reductions in state programmes, are opposed by the UGTT. Tunisia's 2021 budget forecasts borrowing needs of 19.5 billion Tunisian dinars ($7.2bn), including about $5bn in foreign loans. But Tunisia's credit rating has fallen since the coronavirus pandemic began, and market concerns about its ability to raise funds are reflected in sharp price rises for Tunisian credit default swaps – insurance against default on its debt.