How politicians must wish the issue of MPs' pay were still hidden in the long grass where they kicked it four years ago after the expenses scandal.

It is not hard to see that the idea of accepting an 11% one-off pay hike must seem to MPs like an invitation to draw big fat targets on their own backs. How can they talk of "difficult choices for us all at a time of austerity" when they are getting a £7600 pay rise? No, no, their reasoning goes, we cannot accept it. Best ignore the issue altogether.

The trouble with that response is that it does not solve the problem, it simply defers it, and the longer any pay increase is deferred, the larger the gap is likely to become between the pay of MPs and other senior professionals. Ever since the Independent Parliamentary Standards Authority (Ipsa) brought forward its proposals to increase MPs' pay, there have been howls of outrage about it, but turn down the volume on that and what is left is the difficult truth: that MPs are underpaid and have been for years.

Theirs is a grave responsibility. MPs carry out their duties in the relentless and unforgiving glare of publicity, usually splitting their time between London and other parts of the UK at significant cost. They occupy an office that ought to command respect and should be a position that others aspire to, yet their salaries fail to reflect the status of that office. Backbenchers' pay falls below that of some secondary school head teachers and many senior civil servants, and within the context of central London the disparity is even greater. That is why the proposed pay rise is fair and why MPs' pay should be increased further in future. Where Ipsa is wrong is in advocating a one-off pay rise of 11% in 2015; David Cameron is right that this is not on at a time of public-sector wage restraint. Instead, the rise should be phased in over a number of years, after which MPs salaries would be linked to average earnings.

At the same time, MPs must take a hit on perks. Expenses rules on items like food and TV licences should be tightened, resettlement payments worth tens of thousands scrapped and the current final-salary pension scheme MPs enjoy changed to a career-average one while their contributions are increased. It would make MPs' remuneration more transparent and, crucially, taken alongside the pay increase, would be cost-neutral to the taxpayer.

This issue must be tackled once and for all. Why? Because the make-up of the House of Commons matters. A YouGov poll showed more than two-thirds of MPs believe they are underpaid. If talented individuals believe they are getting less than they deserve or could command in another job, other potential candidates will think twice about standing for election. The worst-case scenario if MPs' pay is allowed to continue falling behind is that the proportion of independently wealthy politicians could increase, making Parliament less representative. With a cabinet already overburdened with millionaires, that is the last thing British democracy needs.

Ipsa was set up to end the practice of MPs setting their own pay. Now it finds itself being as good as threatened with abolition by the Prime Minister because he does not like its findings. How absurd. At some point, Parliament and Government must grasp this nettle. This is the time.