Nick Hargrave is a former Downing Street special adviser, where he worked under both David Cameron and Theresa May. He now works at Portland, the communications consultancy.

There is always a tendency in politics to over-correct from the last big mistake. That is certainly the case in Conservative politics when it comes to the art of preparing manifestos.

It is commonly held that the 2017 Conservative Manifesto was a sub-optimal political product – where unpopular and untested policies were unleashed on an unsuspecting electorate. This, so the argument goes, is the reason why the Conservative Party blew a massive poll lead and Jeremy Corbyn came within a sniff of high office.

Learning from this experience, Tory staffers will be leaving nothing to chance this time. A robust political stress-testing operation will dominate the 2019 manifesto process. The signature policies will be focus-grouped within an inch of their life. Hardened and cynical characters from the party’s research department will draw up long lists of difficult questions; these attacks will in turn be tested in focus groups. Anything that goes down badly in Bishop Auckland and Crawley will be noted down in red pen. Safety first will be the overwhelming mantra of the day.

I would argue, however, that there is a danger in over-correcting too much. The 2017 manifesto in its totality was bad politics and an unforced error. However, commentators have over-simplified why it went down so badly. It was not just because the infamous social care policy – the so called ‘dementia tax’ – was unpopular.

Part of the problem with the social care debacle was that it came out of nowhere; difficult issues need time to breath and be socialised.

There is also a convincing argument that Theresa May’s weak and wobbly defence of the u-turn – ‘nothing has changed’ – did as much damage to her proposition at that election as the policy itself.

And it should not be forgotten either that a further deficiency of the 2017 manifesto was its lack of retail friendly, sunny measures to balance the more difficult choices the country faced.

Looking further back in history, there is good evidence that voters will back politicians advancing difficult arguments if they are convinced that they will be competent in their delivery and well-motivated in their values.

This is the test of leadership. Margaret Thatcher’s ambitious privatisations are held up nowadays as a vote-winning policy that spoke to a bracing desire for 1980s-style freedom. In reality, privatisation was more contested and controversial; IPSOS Mori found in 1989 that it was the third most unpopular policy of her tenure behind the poll tax and funding of the NHS. The Conservative commitment to continued deficit reduction in the successful 2015 campaign could be viewed through a similar prism.

At this election, I am not suggesting that the Conservative Party should deliberately court unpopularity. Nor, with a month to go, am I saying that it would be electorally wise to mic drop a wealth tax or breaking up the NHS into the national conversation.

But I am arguing that there is some limited space for radical candour with the electorate on the difficult choices facing the country in the 2020s. If the party fails to signpost these choices at all in its manifesto, then it will find it more difficult to govern than would otherwise be the case. The country will also be badly served given the importance of some of the decisions ahead.

Given the political realities, my preference would be for the manifesto to commit on its back page to a new unit in government under the responsibility of the First Secretary of State. If you wanted to capture attention you could call it the “The Too Difficult Department”. If you wanted to be sober, you could call it the Long-Term Challenges Unit working out of the Cabinet Office. There will already be civil servants whose job it is to think about these things; but it should be the defined responsibility of elected ministers.

The new creation would be founded with the overarching principle that there are some debates our country needs to have but are too controversial and politically explosive to move immediately. I can sort of see Boris Johnson making this case with a unique blend of gravity and humour.

This institution would not deliver any change over the course of five years. Its role would be to think and – more critically – communicate. It would be a focal point for these difficult debates to progress at a controlled pace; probably drawing in citizens’ assemblies to help it deliberate. The conclusion of those debates should in turn form the bedrock of the Conservative Party’s manifesto for the putative election in 2025. Too far in the future some might say – but politics is the art of the possible.

I would in turn isolate this down to five politically difficult issues:

  • How to fund public services given the pressures of an ageing society and ever-increasing consumer expectations. In the near term, the IFS estimate that the NHS will account for almost 40 per cent of all public spending by 2023/24. By the second half of the twenty-first century, the OBR estimate that our debt profile is likely to balloon to eye watering levels well beyond our GDP.
  • Whether increasing inequality of outcomes over the last 40 years – under successive governments – is tolerable or something that needs to be addressed. This is really what drove Brexit. Addressing this will be far less about our future relationship with the Customs Union and far more whether we are willing to have difficult conversations about the taxation of wealth and property.
  • Decarbonisation and whether we are really serious about transitioning to net-zero carbon emissions– which will probably have to involve road charging, eating less meat and linking environmental behaviour to corporate and personal tax rates.
  • The long-term view on automation and what needs to be done to make the most of its disruptive effects – including whether we should incentivise urbanisation in cities as an overriding policy priority.
  • Consideration of whether new global institutions where we pool our sovereignty are needed in order to tackle new macro challenges such as the impact of technology and tax avoidance.

Manifesto day for the Conservative Party should be primarily designed around the retail package it is offering voters for the next five years. But amongst the barrage of jam today and the promises of an easy life, I would suggest that there is both space and an imperative to look a little beyond. Voters are many things but they are not stupid. A manifesto commitment of a ‘Too Difficult Department’ is unlikely to win the next election for the Conservative Party. But it might just help it retain its reputation as the serious party of government in elections to come.