Tunisia's president on Tuesday accused the prime minister of seeking power through a secret deal with an Islamist party, the latest sign of tension at the top ahead of elections.Prime Minister Youssef Chahed had gained the backing of the Ennahdha party to stand in the presidential polls, President Beji Caid Essebsi said, quoted by Al Arab newspaper."Chahed wants to stay in power... Ennahdha has understood his ambition... They have pushed him to create a new party which divides power between them after the 2019 elections," said Essebsi, whose comments were verified by the presidency.Chahed was appointed by Essebsi in 2016 but relations between the pair have strained in recent months, fuelling speculation the prime minister will run in this year's presidential election.For his part, 92-year-old Essebsi indicated he would not seek a second term."My ambition is not to stay president for life. I am not in favour of a president for life," he said.Essebsi's claim of a private pact by Chahed comes as the premier prepares for elections with a progressive platform - the Tahia Tounes movement - described as being in opposition to Ennahdha.Its political stance is similar to that of Essebsi's secularist Nidaa Tounes, which won the 2014 elections and formed a coalition with Ennahdha that lasted four years.Nidaa Tounes has since split and its leader, Essebsi's son Hafedh, has been battling to oust the prime minister for months.Sign up to News24's top Africa news in your inbox: SUBSCRIBE TO THE HELLO AFRICA NEWSLETTERFOLLOW News24 Africa on Twitter and Facebook.