Opposition treasury spokesman Malcolm Turnbull says Opposition Leader Brendan Nelson should be given a fair go in the job, despite disappointing results in recent opinion polls. 

Speaking on ABC1's The 7.30 Report, Mr Turnbull said the lack of support for the Opposition and its leader is not surprising soon after an election defeat. 

He says the Federal Government's honeymoon period will not last forever. 'These are the tough days, these are the dog days for an Opposition,' he said. 

'Brendan sought the leadership, he volunteered for it, he got it. 'It's a tough gig and he is going through a tough time, but better times will come.' 

Give Nelson A Fair Go: Turnbull