Israel's Labour party leader has appointed Raleb Majadele as science and technology minister - making him the first Arab Muslim in Israel's cabinet.
Mr Majadele said his nomination was "great news for the Arab public"
Amir Peretz said the "historic" appointment would improve relationships among different groups in Israel.
Mr Majadele replaces Ophir Pines-Paz who quit last October in protest at the addition of ultra-nationalist party Yisrael Beitenu to the coalition.
However, Mr Majadele's appointment has drawn angry criticism.
Esterina Tartman, chairman of Yisrael Beitenu, said Mr Majadele's appointment was a "lethal blow to Zionism", the Haaretz news website reported.
The comments have prompted lawmakers to call for the ultra-nationalist party to be expelled from the coalition government led by Prime Minister Ehud Olmert.
Yoram Marciano, Labour's parliamentary chief, called on Mr Olmert to oust Yisrael Beitenu and for Labour to reconsider whether it can "sit in the government with this racist party".
"No believer in equality and democracy can accept them being on the agenda," said Michael Eitan of the Likud opposition party.
Arab citizens of Israel make up about 20% of Israel's estimated population of seven million.
"This is a historic development and undoubtedly it will bring about an improvement in the relationships among different groups in Israel," Mr Peretz said following the announcement.
The Labour leader also said Mr Majadele's inclusion in the cabinet will balance the presence of ultra-nationalist Avigdor Lieberman, leader of Yisrael Beiteinu.
"It's great news for the Arab public. It's a correct step in the direction of equality. We have many challenges ahead of us," Mr Majadele said.
The Israeli press is speculating that the appointment of Majadele will allow Mr Peretz to rally support among Israeli Arab citizens of Israel ahead of party elections in May.
The Labour party has seven ministers in the Israeli cabinet.
An Israeli Druze, Salah Tarif, was appointed minister without portfolio in 2001.