The United Synagogue president, Stephen Pack, has said that applications to be chief rabbi were still being accepted despite the March 5 deadline specified in an advertisement for the job.

Mr Pack, who is chairman of the Chief Rabbinate Trust, which is responsible for appointing Lord Sacks's successor, said it had received some "outstanding" applications, but added: "We are still expecting a number of applications to come in."

He said that the ultimate deadline was September 2013 when Lord Sacks intended to retire. "If we had to say we'd like him to stay on for six months, we'd do that. This is the most important decision affecting the community in a generation and we have to get it right."

But he predicted: "We won't have any dfficulty" in filling the post.

The first round of interviews is due to take place in May. Mr Pack would not disclose the number of applicants so far, while those involved in the recruitment process have had to sign confidentiality pledges to protect the identity of candidates. "There are some people who would not apply if they felt it was going to be sprayed all over the press," he said.

Israel's former Diaspora Affairs Minister Rabbi Michael Melchior, who has been widely tipped as a potential candidate, revealed this week: "I have not applied, formally or informally".

But he added: "As a politician, I learned that you never say never."

Within the UK rabbinate, a strong body of support is emerging for Rabbi Ephraim Mirvis of Finchley Synagogue to become the next Chief. Now 55, the former Chief Rabbi of Ireland might once have been considered too old for the post, but that is no longer such a factor with the lifting of the retirement age.

The other British rabbi thought to be in contention is Rabbi Harvey Belovski of Golders Green Synagogue. Oxford University and Gateshead Yeshivah-educated, he has a doctorate in Chasidic thought.

A number of modern Orthodox rabbis in America have also been the source of speculation among the rabbinate. They include: Rabbi Jacob Schachter, senior scholar at Yeshiva University's Centre for the Jewish Future; Rabbi Michael Broyde, a professor of law and religion at Emory University, Atlanta and dayan on the Beth Din of America; Rabbi Jonathan Rosenblatt of the Riverdale Jewish Centre, a large community in New York; and Rabbi Meir Soloveitchik, of another leading congregation, Kehillath Jeshurun in New York.

Also believed to be in the running is Rabbi Daniel Beller, formerly of Edgware, leader of an Orthodox congregation in Ra'anana, Israel, and involved in projects to bridge the religious-secular divide. But another British ex-pat, Rabbi Shaul Robinson, who moved from Barnet Synagogue to the prestigious Lincoln Square congregation in New York, has ruled himself out. "Our family is settled here and our new shul is opening before the Yomtovim," he said.

Chief Rabbi Warren Goldstein – thought to be a favourite of the London Beth Din – has also said he has not applied, citing "responsibilities and commitments" at home.