Some 200 electricians gathered at the Balfour Beatty site at Blackfriars in central London on the day of the public sector general strike last week.
Electricians marched, despite police opposition, to join Prospect, PCS and FDA union members picketing at the Health and Safety Executive.
More than 100 people from the Occupy London camp joined them.
They then marched to meet Unison members on a Southwark council picket line.
Next they marched to St Thomas’ hospital and the Tate Modern art gallery.
Last week also saw protests in Hull and Glasgow.
Around 200 electricians met in Glasgow last Saturday to discuss Balfour Beatty bosses’ attempts to stop them striking.
Immediately after the meeting they marched down to a Balfour Beatty site in Sauchiehall Street in the heart of Glasgow’s shopping area.
From there the protest wound its way through the busy Christmas shoppers to applause.
The protest entered George Square and occupied an NG Bailey site.
Thanks to Alistair MacPhee