Jim Chalmers has warned there will be little room for more cost of living support in his fifth and “most responsible” budget yet, as he ruled out an immediate extension of the 26-cent cut to the fuel excise and downplayed hopes for additional tax relief for workers. The treasurer also said Australian voters would forgive Labor for breaking a pre-election vow not to touch negative gearing rules for landlords, which is set to form part of a package that would also scale back the capital gains tax discount in the name of intergenerational fairness. As the Reserve Bank’s monetary policy board began its two-day meeting that most economists predict will end with a third straight interest rate hike on Tuesday , Chalmers promised that the budget in a week’s time would play “a helpful, not a harmful role in the fight against inflation”. “Australians are already paying a very hefty price for this war in the Middle East. We had some inflationary pressures in our economy before the war.…