Train users across Sydney’s north should know in the next few months how long the Epping to Chatswood rail line will be out of action during construction of the north-west link.

The Epping to Chatswood line, which opened in 2009, could be shut down for months so it can be upgraded to accommodate the new train line to Rouse Hill being built by the Baird government.

The shutdown will affect an estimated 14,000 people each day. Credit:Jon Reid

But Transport Minister Gladys Berejiklian has not confirmed the length of time the line will be closed, saying it is a matter of negotiation with the new operator of the north-west rail link.

Those negotiations, Ms Berejiklian said on Tuesday, should soon be completed.