Frustrated rail commuters faced peak-hour delays of up to 15 minutes in Melbourne’s south-east this morning, as new figures reveal train operator Metro has failed to meet punctuality targets for its seventh consecutive month.

Trains on the Cranbourne and Pakenham lines ground to a halt at 8.10am after power was cut to the overhead wires between Westall and Clayton stations.

Metro spokesman Chris Whitefield said the outage lasted only eight minutes, however it caused knock-on delays of up to 15 minutes for other services on the lines during peak hour.

Two faulty trains at Frankston also caused delays of up to 10 minutes on the Frankston line this morning, while Mr Whitefield said at least three other trains were cancelled across the network.