A union representing 100,000 workers has voted to split from the Australian Council of Trade Unions and set up a rival body, in an escalating response to the CFMEU being pushed into administration.

The Communications, Electrical and Plumbing Union (CEPU) supported a vote to separate from the ACTU on Thursday afternoon.

The decision was made in protest to the peak union body's support for federal government laws forcing the CFMEU into independent administration.

The laws were introduced after the government concluded the union would not comply with court action to impose administration.

The union has faced allegations of bikie and underworld infiltration, corruption and bullying.

ACTU president Michele O'Neil said the union was disappointed by the CEPU's move and defended its position on the CFMEU.

"The ACTU have at all times urged the CFMEU Construction division leaders to act decisively to ensure their union was free of criminal elements," she said.

"Unfortunately, those who had the power to act failed to do so.

"ACTU decisions are made at our executive where all unions are represented."

The CEPU has vowed to hold a summit of blue-collar unions within the next three months as part of an endeavour to set up a rival to the ACTU ahead of the next federal election.

It is attempting to secure the support of other ACTU affiliated unions as part of that process.

The Australian Manufacturing Workers Union's (AMWU) national secretary Steve Murphy said his union was disappointed by the CEPU's move.

"Whilst each union has its independence, autonomy, and relevance within our respective industries — the interdependence of our union reflects our shared experience of unity, solidarity and discipline," he said in a statement.

"These relationships are important to share and defend — as we uphold our values and ambition.

"The ACTU is where the collective voice of Australian unions come together to assert our interests."

The Mining and Energy Union has also reaffirmed its support for the ACTU.

General president Tony Maher said the union did not support the establishment of an alternative grouping of blue-collar unions.

"Sally McManus and Michele O'Neil continue to provide excellent leadership to our movement and they have overseen a period of extraordinary wins for working people," he said.

"The ACTU has the full confidence of the MEU and the majority of the movement.

"In a number of countries there are multiple peak councils. Australia has a proud tradition of a united labour movement and we believe this is the best way to serve working people."

The ABC has approached the CEPU and its subsidiaries for comment.