The state’s transport department knew utilities provider Ausgrid was working to change guidelines for dealing with underground cabling on George Street prior to signing a construction contract for Sydney’s new light rail line – an issue at the heart of delays to that project and a $1.2 billion legal fight.

The question of who knew what and when about Ausgrid’s attitude to underground utilities is not only relevant for political point-scoring over the trouble tram line, but is also relevant to accountability over the cause of delays, as well as potentially relevant to litigation over financial responsibility for those delays.

In a parliamentary hearing on Monday, Ausgrid executives said they provided drafts of new guidelines they had prepared for dealing with George Street utilities to Transport for NSW executives at multiple meetings in February 2015.

Construction work for the light rail project along George Street between Alfred Street and Bridge Street. Credit:Steven Siewert

“We were working on drafts with Transport for NSW on 9, 19, 20 and 23 February,” Richard Gross, the chief executive officer at Ausgrid, told the inquiry.