The Coalition holds a crushing lead over Labor in the must-win federal seat of Gilmore, catapulting Liberal incumbent Joanna Gash to an election-winning position after just one week of campaigning.An exclusive Mercury/IRIS poll of 400 voters this week shows Mrs Gash is ahead of Labor's Neil Reilly by 58 per cent to 31 per cent in the primary vote, with Greens candidate Ben van der Wijngaart trailing on 11 per cent.On a two-party preferred basis, Mrs Gash holds a commanding 60-40 lead over Mr Reilly, which would deliver her a hefty 10 per cent margin on August 21 and transform the seat into a Liberal stronghold.For full story see Saturday's Mercury.