By Chaminda Jayanetti

With the Queen's Speech set for Wednesday and Theresa May still without a confidence and supply deal with the DUP, questions are being asked as to whether the government can actually hold.

Reportedly, the DUP has agreed to support the government in a confidence vote – meaning that it doesn't fall – but not on the 'supply' side. In other words, there has been no agreement yet over Budgets.

This is no great surprise  – after years of power-sharing in the cauldron of Stormont, following a tortuous peace process to which they were opposed until it suited them, the DUP are the most experienced deal-cutters in Westminster.

Northern Ireland has high levels of poverty and was hit by funding cuts under austerity, so the DUP is entirely within its rights to hold out for every last penny it can get.

As the Independent's Jon Stone points out, however, under the Fixed Terms Parliament Act, losing a Budget vote doesn't automatically count as a vote of no confidence that brings down the government.

Instead, there has to be a specific vote of confidence – on which the DUP, no doubt alarmed at the prospect of a government led by Sinn Fein's old ally Jeremy Corbyn, has apparently pledged to back the government.

So what happens if May secures a confidence deal with the DUP, but can't tie up the supply part? Do we get a government with no Budget and no legislation?

Not necessarily – as long as the DUP doesn't actually vote against it.

The current state of the parties after the election is that the Conservatives have  317 MPs. The DUP have ten. Sinn Fein's seven don't show up. The Speaker doesn't vote except in a dead heat – in which case he backs the government.

What does that leave? 262 Labour MPs, 35 from the SNP, 12 Lib Dems, four from Plaid Cymru, Caroline Lucas of the Greens, and independent Northern Irish (moderate) unionist Sylvia Hermon.

That's 315. The Tories would have a majority of two.

Factor in the three deputy speakers who don't vote on legislation – one Tory, two Labour, for as long as ex-Tory John Bercow remains Speaker – and the figures shift to 316 Conservatives against 313 opponents.

On that basis, the Conservatives would be able to pass a Queen's Speech, Budget and legislation without DUP support, as long as the DUP abstains rather than voting against them.

But it would also require absolute, 100% unity among the Conservatives – not something the party has ever been known for.

Of course, any disunity among the assorted opposition MPs – pro-Trident or pro-Brexit Labour MPs breaking ranks, for example, or perhaps an accidental meeting of minds with the Lib Dems – would give the Conservatives marginally more wriggle room on the maths.

It doesn't make for strong and stable government. It barely makes for government at all. The amount of legislation that could get through would be even less than the trickle that would pass with the DUP's backing.

The record of the last seven years suggests that may not be a wholly bad thing.

Meanwhile, irascible Tory backbenchers would come back again and again to demand quid pro quos in return for their support on specific bills – pertinent at a time when local NHS hospitals are facing cuts and closures.

A prime minister who failed to get a Budget past her own MPs could not survive the end of the week, mind – at the very least, a new Conservative leader (and thus prime minister) would have to follow. The government could carry on constitutionally, but politically it would be a laughing stock.

Not that brass necks are in short supply in Westminister.

One final irony – the Conservatives' general election manifesto pledged to get rid of the Fixed Term Parliament Act. Their survival in government increasingly depends on keeping it.