Around 150 angry sparks demonstrated outside Tate Modern this morning

Controversial changes to electricians’ pay and conditions will go ahead “with or without” union support, a spokesperson for the firms at the heart of the row has said.

The news comes as around 150 angry electricians demonstrated outside the Tate Modern art gallery on London’s South Bank this morning, in an eighth week of protests over proposed changes to workers’ pay and conditions.

One of the protesters told Building the group crossed Millennium Bridge and blocked off traffic on the busy Cannon Street road adjacent to St Paul’s Cathedral for up to fifteen minutes, until the disruption was stopped by police.

He added there was a “heavy police presence” at this morning’s demonstration and that officers had barricaded the entrance to the construction site adjacent to the Tate Modern, where Mace is building an extension to the gallery.

Eight of the industry’s largest electrical contractors – including Balfour Beatty and NG Bailey – have agreed to ditch a 40-year-old wage agreement between employers and workers in favour of drawing up a new agreement.

Five of the eight breakaway firms have put its electrical workers on notice and given until 7 December to sign up to the proposed new Building Engineering Services National Agreement (BESNA) or face redundancy.

Union Unite opposes the changes and claims workers face a pay cut if the contractors get their way.

But Blane Judd, chief executive of the Heating and Ventilating Contractors Association and nominated spokesperson for the companies, said the changes would go ahead “with or without” union support.

Judd added the firms were confident the plans would be backed by the 6,000 workers affected.

He dismissed the demonstrators, claiming they were “seasoned protestors” who were not affected by the issue.

He said the contractors were open to negotiating with the union if it “brought a list of specific concerns” about the proposed new agreement. The BESNA would not result in any worker taking a pay cut, he added.