WASHINGTON (Theguardian) -  President Barack Obama's choice to be his next defense secretary jumped a key hurdle on Tuesday as a Senate committee voted in favour of his nomination.

However, argument over the contentious choice of the former Nebraska Republican senator Chuck Hagel shows little sign of calming down.

The powerful Senate Armed Services Committee voted by 14 votes to 11 to recommend the nomination of Hagel, who has faced an intense grilling from the panel over a wide range of issues from his former Republican colleagues. He is aiming to replace the departing Pentagon chief Leon Panetta.

But the matter is not yet fully settled. Hagel's nomination will now move to the Senate where some Republican leaders have vowed to hold up his nomination in the narrowly Democratic-controlled chamber by demanding a super majority to approve him. That would force Democrats to get at least 60 votes in support of Hagel – meaning they will have persuade some Republicans to vote for him.

The Democratic chairman of the Senate committee, Michigan senator Carl Levin, urged Hagel's acceptance. "The defeat of this nomination will leave the Department of Defense leaderless," he said. Levin added that a recent nuclear test in North Korea had shown the urgency of getting through the process. "We need a secretary of defense. We have the use of a nuclear weapon in North Korea," he added.

But Republican critics on the committee continued their ferocious and sustained attack on Hagel as they debate whether or not to recommend him.

They criticised Hagel for being too unenthusiastic a supporter of Israel and of being soft on Iran. South Carolina senator Lindsey Graham said the hearings had painted an "unusually disturbing picture" of the man set to head the Pentagon and his record on voting and supporting certain issues. "It is a series of votes – an edge to him – that makes many of us unnerved … they are very few people who have been so wrong about so many different things," he said.

Other Republican critics said that Hagel had not been forthcoming on the subjects and content of speeches he had been given or all the sources of his income. "His failure to answer specific questions that I asked was very disturbing," said Arizona senator and one-time presidential candidate John McCain.

Meanwhile, Oklahoma senator Jim Inhofe said he felt Hagel had tried to cover up previous stances on key issue like Iran and Israel and how to deal with nuclear weapons and given different answers in front of the committee. "My problem is that is not what he said and not what he lived in the past … I still oppose his confirmation," he said.

It is now expected that Hagel's nomination will be voted on in the Senate as early as Thursday. Most experts believe the furious debate over filling the post will then end and Hagel will be able to take up his new job. Some of his harshest critics, such as McCain, have said they oppose a move to delay his appointment in the full Senate despite voting against him. Meanwhile, several moderate Republicans such as Thad Cochran of Mississippi and Mike Johanns of Nebraska have said they will back Hagel.