There's a moment I remember well from the Theresa May manifesto launch in 2017.

Speed reading through the booklet for the first time, one of the former prime minister's aides sidled up to me and rather proudly pointed to a paragraph which he said was the kernel of the document.

A section that sought to recast Conservatism in the image of the prime minister's political philosophy - Mayism if you like. "We do not believe in untrammelled free markets. We abhor social division, injustice, unfairness and inequality. We see rigid dogma and ideology as not just needless but dangerous."

A clean break the from the Cameron years, this was a prime minister who was trying to shift to a more interventionist state, as she admitted investment in public services required sacrifices elsewhere.


Image: Theresa May tried to shift to a more interventionist state

Mrs May abandoned promises by her predecessor not to raise income tax or national insurance, while scrapping blanket protections to pensioners' incomes and asking elderly people with over £100,000 in assets to pay for their own care out of the value of their homes. In return there was more money for schools and a commitment to increased spending in the NHS.

It was a truthful, ambitious manifesto that set out her stall. But it backfired badly as Mrs May's social care policy unravelled and so, ultimately, did her campaign.

Fast-forward two years and Mr Johnson is, on the face of it, promising something similar to Mrs May - using Brexit as an opportunity to reshape the nation.

But this time around, the prime minister hasn't backed up his headline promise - Get Brexit Done and unleash Britain's potential - with any detail on what he actually wants to do with a five-year term.

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There is no big vision and no nod to any political philosophy, beyond his verbal references to being a "One Nation" Conservative. In making his manifesto risk-free, he has left the public voting blind when it comes to what Boris Johnson's Britain looks like.

We don't really even know what his Brexit looks like. "Get Brexit Done" doesn't really travel beyond Mr Johnson's promise to pass his divorce deal through parliament before Christmas and formally exit the EU by 31 January.

This will mean the UK leaves the EU and moves into an "implementation period" until the end of 2020 in which the UK has to follow most EU law as the two sides negotiate a post-Brexit trade deal.

In making his manifesto risk-free, he has left the public voting blind when it comes to what Boris Johnson's Britain looks like.

As for the details of the deal, that is still to be hammered out. Mr Johnson is clear on four things: the UK will be out of the single market; out of any form of customs union; out of the jurisdiction of the European Court of Justice; and out of the transition period - deal or no deal - by the end of December 2020.

His critics say this deal will be fiendishly difficult to negotiate and will not be ready by the end of next year, while a "do or die" December 2020 exit could harm the economy and increase the debt and the deficit.

And, as the think-tank Britain in a Changing Europe points out in its Brexit manifestos report, the party doesn't factor in what leaving the EU might mean for their wider economic plans. With that in mind, Getting Brexit Done might not be quite as simple as the prime minister would like you to believe.

Brexit and how it is, or isn't, done of course has huge reach across to the UK economy, our society and even the future of the Union. But these issues have been set aside for campaign purposes.

Instead, the prime minister has promised to "unleash our potential" in a post-Brexit Britain. But what about those domestic plans?

There is a commitment to more money for schools, police and hospitals. But dive into the detail and the Conservatives are committing just £2.9bn extra a year on day-to-day spending by 2023/24. That doesn't mean the Conservative party is about to return to austerity or eliminate the government deficit. There was a big increase in day-to-day spending in the 2019 spending round, while the party is planning to spend up to £100bn on new capital investment projects.

But in current spending, which has a more immediate impact on peoples' lives, the Tory commitments in the manifesto were small change. Across public services, there is a promise to recruit 20,000 more police officers, but this is effectively just replacing the 20,600 cut from the frontline between March 2010 and March 2019.

And on the NHS, a promise to increase the number of nurses by 50,000. But even this stoked controversy after it emerged the number of new recruits actually amounted to 31,000 (19,000 of this figure was based on retaining nurses the NHS has already got). This is a safety-first manifesto, where scant spending promises are matched with a promise not to raise income tax, national insurance or VAT.

But might this change if the Conservatives get a big majority? Paul Johnson, director of the Institute of Fiscal Studies, pointed out last week it was "highly likely the Conservatives would end up spending more than their manifesto implies and thus taxing and borrowing more".

"The chances of holding spending down as they propose over a five-year parliament look remote. Why have they been so immensely modest in their proposals? Because to do otherwise would either mean resiling from their pledge to balance the current budget or would mean being upfront about the need for tax rises to avoid breaking their pledge."

There are other big holes - and perhaps big traps - in the Conservative manifesto. One great tax-and-spend hole is social care. Mr Johnson pledged on the steps of Downing Street that he "will fix the social care crisis once and for all" and promised a "clear plan" only to shelve that in the manifesto, promising £1bn-a-year for social care while promising no-one will have to sell their home to meet the costs of their care. The IFS said his promise was an "uncosted aspiration". Mr Johnson clearly not wanting to rock the boat.

And what about traps? Lawyers worry that Mr Johnson might want to clip the power of the courts if he wins a five-year term. Buried on page 48 of the manifesto is a section that promises to "look at the broader aspects of our constitution: the relationship between the government, parliament and courts; the functioning of royal prerogative; the role of the House of Lords; and access to justice for ordinary people".

Image: Labour's manifesto 'leaves you in no doubt about what sort of Britain Mr Corbyn wants to build'

Dominic Grieve, the former attorney general now running as an independent in this election, fears this could amount to an attack on the courts. Might Mr Johnson use a victory to claim a mandate to reform the Supreme Court after it ruled unanimously in September that he abused his powers and acted unlawfully when he suspended parliament? Might he reform the House of Lords to limit its powers of legislative scrutiny?

From the NHS to our police, our schools, our prisons, our courts, this election is far more than just Brexit. The victor will have a five-year term to set the course for how our public services are run and paid for; how our parliament interacts with our courts and with our government; how our elderly are cared for and our children educated.

Love it or loathe it, Labour has at least set out a detailed - and eye-wateringly expensive - plan for Britain in its manifesto. Read it and you are left in no doubt about what sort of Britain Mr Corbyn wants to build. Mr Johnson has done the opposite. His manifesto offers barely an outline of what he wants to do with the country let alone the full picture. He perhaps needs to keep it sketchy in order to help him navigate through the economic uncertainty Brexit will bring.

Britain in a Changing Europe calculates that leaving the EU with a Johnson-style free trade deal will lead to an annual fiscal shortfall of £6bn to £20bn, while a World Trade Organisation exit at the end of 2020 could push that as high as £28bn. With such unpredictability, you can see why the prime minister has attached a blank cheque manifesto to his headline Brexit pledge.

Sky Views is a series of comment pieces by Sky News editors and correspondents, published every morning.

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