Move likely to prompt strong opposition from Republicans who feel Hagel, a former GOP senator, is too liberal on foreign policy

Barack Obama is poised to nominate as defence secretary early next week a Vietnam combat veteran and former Republican senator, Chuck Hagel, in a move that would provoke strong opposition from Republicans and spark a tough nomination battle.

Hagel, though he was a Republican senator, takes a liberal position on many foreign policy issues and was one of the leading voices in his party against George W Bush's Iraq policy.

He had been approached by the White House about replacing Leon Panetta as defence secretary and successfully vetted.

Obama, in an interview last Sunday, spoke highly of him but said he had not made up his mind. "I've served with Chuck Hagel. I know him. He is a patriot. He is somebody who has done extraordinary work both in the United States senate, somebody who served this country with valour in Vietnam," Obama said.

Various sources in the administration and friends of Hagel said the president finally made his decision last week and an announcement will be made on Monday or Tuesday. NBC also said it had confirmed the news.

Others who had been considered included the former under-secretary for defence Michele Flournoy.

Obama announced before Christmas that senator John Kerry will replace Hillary Clinton as secretary of state. While Kerry will almost certainly sail through the nomination process, Hagel's hearings are likely to be more awkward.

The main opposition to his appointment comes from Republicans, who see him as insufficiently supportive of Israel and intent on recalibrating the US position to take more account of Arab opinion.

As a former infantry sergeant, Hagel takes a dovish approach to conflict, being a strong advocate of talks with Iran rather than military strikes over its disputed nuclear programme, potentially the biggest foreign policy issue of Obama's second term.

As defence secretary, Hagel would not be directly responsible for either diplomatic moves involving Israel-Palestine or Iran. But as defence secretary he would have a voice at the table. In the case of Iran, he would also have to provide the military muscle to back up diplomatic moves by Obama and Kerry.

One of his biggest challenges for the incoming defence secretary will be be to oversee a huge reduction in spending planned for the Pentagon. Even though US involvement in the war in Iraq is over and its role in Afghanistan winding down, the administration is seeking deep cuts, especially in big, expensive air and sea projects, one that would be heavy resisted by the defence industry and by members of Congress who fear job losses in their states and districts.

Republicans predict there will be few votes for Hagel from their side in the nomination process.

GOP senator Lindsey Graham, of South Carolina, told Fox last week that though all of them liked Hagel as a person, "I think a lot of Republicans and Democrats are very concerned about Chuck Hagel's positions on Iran sanctions, his views towards Israel, Hamas and Hizbollah – and there is wide and deep concern about his policies". © Guardian News and Media 2013

[Image: Flickr user Secretary of Defense, Creative Commons licensed]