Senator George Voinovich, whose reservations about Bolton prematurely scuttled a vote on the nomination by the US Senate's Foreign Relations Committee last month, expressed "great concern" about Bolton's nomination for the influential post, telling members of the panel that making Bolton Washington's UN envoy would send a "negative message to the world community".
In surprisingly harsh remarks, Voinovich said on Thursday that Bolton was "a poster child of what someone in diplomatic circles should not be".
The Ohio senator said, however, that he would nevertheless allow Bolton's nomination to proceed to a vote before the full Senate, despite grave reservations about allegations that Bolton mistreated staff members during his long career as an official in various capacities in Washington.
Voinovich argued that allegations of Bolton's arrogance and bullying "are the very characteristics that we are trying to dispel in the world community".
He added that had Bolton been a high-ranking official in the private sector, rather than in government, "he would have been fired."
Bolton's nomination could still survive a committee vote scheduled for the end of Thursday's marathon meeting, but Voinovich's strong pronouncement against him ensured a much more difficult ride for Bolton when the full US Senate takes up the nomination.
"[Bolton is] a poster
child of what someone
in diplomatic circles should not be"
The debate in the bitterly divided committee was the latest showdown between Senate Democrats and Republicans, who have wrangled bitterly for weeks over whether to endorse or scuttle US President George Bush's nominee for the influential UN post.
A raft of new allegations swirled around Bolton since the committee vote was suspended last month. Democrats continued to press for additional information about the career State Department official -documents that US officials refused to supply.
If approved, Bolton would become one of Washington's most visible foreign policymakers on virtually every major issue, from nuclear programmes in Iran and North Korea to the future of the world body itself.
In the case of a tie, the foreign-relations panel could still send the nomination to the full Senate - where Republicans hold a 55-44 majority - but without a positive recommendation.
Bolton supporters acknowledge that he has at times been a bit "blunt", but they say his direct manner is just what is needed to help whip the scandal-plagued UN into shape.
But even his ex-boss, former secretary of state Colin Powell, reportedly told lawmakers that Bolton - who is currently undersecretary of state for arms control and international security - had been a problematic official.
And Powell's former chief of staff was quoted by the US press as saying that Bolton would make an "abysmal ambassador".
Even supporters admit Bolton
at times has been a bit 'blunt'
The panel has spent weeks examining allegations that Bolton misused or hyped flawed intelligence on some of the world's hotspots, including China, Iran, North Korea and Syria.
All eight of the panel's Democrats have vowed to vote against Bolton, while four of the Republicans on the committee -including Voinovich - have expressed doubts.
The White House, meanwhile, has launched a an all-out media offensive to persuade members belonging to Bush's party to get in line.