Umno president Najib Razak has been too "polite" and needs to be firm in order to set things right in the party, said a senior member.

Umno supreme council member Mohd Puad Zakashi reflecting on the party's "humiliating defeat" at this week's general election blamed the party's cronyism and warlords for crashing out of power that saw a change in government for the first time in half a century.

"Najib must realise a tough attitude is important (in managing the party)."