Coalition MPs heading to Canberra for Tuesday's first party room meeting since the budget will push for changes to key measures, among them Tony Abbott's signature paid parental leave scheme and scrapping a proposed increase to the pension age.

As MPs started gathering, they said the government's disastrous budget sales pitch had made it difficult to explain tough measures to voters in their electorates. Senators complained they would not able to voice their concerns in a party room meeting because they would be tied up in Senate estimates.

Treasurer Joe Hockey: "Absolutely committed" to seeing the government's agenda through, "because we must". Credit:Brendan Esposito

Treasurer Joe Hockey signalled on Sunday that the government is not for turning on some of its more controversial policies, including the introduction of a GP co-payment.

Mr Hockey said the government would not back down on the fee but the actual price could be up for negotiation to push it through the Parliament.