Vince Cable faced a hostile reception as he threatened action against strikes at the GMB's conference in Brighton.
Members of the manufacturing union repeatedly heckled and booed the business secretary as he struggled through a speech on the future of industrial relations.
One delegate reportedly walked out at the beginning of his speech and another held up a sign stating that 'Vince is not welcome here', it was reported.
Mr Cable was heckled during a section on employment tribunal reform, but it was his remarks about impending industrial action which prompted the most angry response.
"Later this month, we will witness a day of industrial action," he said. One member of the audience cheered, prompting applause from delegates.
Mr Cable continued by remarking that "the usual suspects will call for general strikes and widespread disruption", before being interrupted by further cheering and applause.
"We are undoubtedly entering a difficult period and cool heads are going to be required all round," he said.
"Despite occasional blips, I know that strike levels remain historically low, especially in the private sector. In the last year to the end of March, there was the lowest number of days effected by industrial action since the early 1930s. And of course the right to strike is a fundamental principle.
"So on that basis, and assuming this pattern continues, the case for changing strike law is not a compelling one.
"However, should the position change, and should strikes impose serious damage to our economic and social fabric, the pressure on us to act will ratchet up," he added, prompting further booing and heckling.
"That is something which both you, and I, will both collectively want to avoid."
The moderator was forced to interrupt Mr Cable, telling the audience: "You may not like it no more than I do, but please listen to what's being said."
Mr Cable's comments come as teachers' unions ballot for a strike over their pensions to take place on June 30th - the same day as a group of other public sector unions have set aside for industrial action.
A decision by the coalition government to legislate against the unions would win support from Conservative backbenchers keen to suppress unrest among public sector workers about their employment conditions.
The decision to switch the indexing of public sector pensions from retail price index to consumer price index, implemented in April, has already prompted major disquiet, however.
With Mr Cable appearing to signal a shift in his personal attitude to industrial relations with today's speech, observers are suggesting a confrontation is increasingly likely in the coming months.
Lorely Burt, co-chair of the Liberal Democrat backbench business, innovation and skills committee, insisted that her party valued trade unions.
"We have seen the damage that violent and sustained strike action has wrought on economies like Greece," she commented.
"No one wants to see the huge job cuts and punitive interest rates which followed their inability to grasp the nettle of difficult economic decisions."