The Yemeni president, Abd-Rabbu Mansour Hadi, has retracted his resignation after escaping house arrest in the militia-controlled capital, an aide has said.

The embattled leader tendered his resignation last month after the Shia militia, known as Houthis, seized the presidential palace and besieged his residence in Sana’a.

On Saturday, he made a surprise escape and resurfaced in Aden, the capital of the formerly independent south Yemen, where he resumed his duties and said all measures taken by the Houthis were “null and illegitimate”.

An aide to Hadi said he had sent a letter withdrawing the resignation to Yemen’s parliament, which had never met to formally accept it.

“I have withdrawn my resignation which I tendered to your esteemed parliament,” Hadi wrote in the letter, a copy of which was seen by AFP.

In the letter, Hadi urged lawmakers to cooperate with him to “salvage the salvageable and to normalise the security and economic situation in all provinces”.

Hadi also called on government ministers to “head immediately to Aden to convene”, the presidential aide said.

The prime minister, Khalid Bahah, had tendered his resignation at the same time as Hadi. He remains under house arrest in Sana’a along with other ministers and officials.

The Houthis, whose power base is in the mainly Shia northern highlands, overran Sana’a unopposed in September.

They have pushed their advance south and west into mainly Sunni areas, where they have met with fierce resistance from tribesmen and Yemen’s powerful branch of al-Qaida.

Hadi is a southerner who spent nearly three decades in the north, serving as defence minister and vice-president. He became president in 2012 after longtime strongman Ali Abdullah Saleh was forced from power by a year-long uprising.