Scottish Labour’s leadership contenders have revealed that they could push for income tax rises.Hopefuls Monica Lennon and Anas Sarwar broke the news while debating their political stances on BBC's The Nine programme on Monday.Ms Lennon said any changes would be part of an overall review while Mr Sarwar claimed he wanted to bring in more money to the public purse by increasing the amount paid by top earners.He added: “I think we need a progressive tax system where we get the powers we need to do