If confirmed, this could result in an approximately £46 million ($69 million/€65 million) hike in Government backing for the agency, from £158 million ($238 million/€225 million) in 2013-17 to around £204 million ($308 million/€290 million) in 2017-2021, raising hopes that Great Britain’s strong recent Olympic and Paralympic performance can be continued at Tokyo 2020.

However, athletes and national governing bodies would be well-advised not to assume that their personal funding packages are now set to go up by 30 per cent, or anything like it, post-Rio 2016.

What appears more likely is that the Chancellor’s unexpected generosity may permit Tokyo cycle Olympic and Paralympic funding to remain at around Rio cycle levels.

This is because of the way a healthy balance of money accumulated by the end of the London 2012 Olympic and Paralympic cycle – when the Exchequer contributed £240 million ($362 million/€342 million) to UK Sport over the four years – is being used to help fund Rio cycle spending.

As at March 31, 2013, UK Sport’s first financial year-end after London 2012, this balance, in the so-called National Lottery Distribution Fund, stood at just under £78 million ($125 million/€99 million).

UK Sport’s 2013-17 financial plan, under which it allocated some £550 million ($830 million/€783 million) of spending over the four years, was “made possible”, according to its 2012-13 annual report, by the “budgeted release of £46 million ($74 million/€59 million) from our Lottery balance over the 2013-17 period”.

That implies that £32 million ($48,000/€46,000) would be left in the kitty post-Rio 2016.

However, minutes to a subsequent UK Sport board meeting suggest that the actual figure might be much lower.

“Current estimated balance at the end of the cycle is £24 million ($38 million/€31 million),” these minutes stated, “and Board agreed that any further reduction presents a risk to the Tokyo strategy but an absolute minimum held should be £15 million ($24 million/€19 million).”

The picture painted in UK Sport’s most recent annual report, for the year to end-March 2015, was rather brighter, with proceeds from the National Lottery – UK Sport’s other main source of income - bouncing back from disappointing 2013-14 levels and the Lottery balance actually edging up to just over £69 million ($104,000/€98,000).

But, the report made clear that it is “forecast to reduce over the remainder of the Rio investment cycle as planned, as the funding requirements of the world-class performance system in the run-up to the Games are met”.

If one makes the perhaps now somewhat pessimistic assumption that the £78 million ($125 million/€99 million) balance in March 2013 will have shrunk to £15 million ($24 million/€19 million) come March 2017, that would mean that £63 million ($101 million/€80 million) of the reserve had been spent over the Rio cycle.

Even if the remaining £15 million ($24 million/€19 million) were applied in its entirety to Tokyo 2020 therefore, a further £48 million ($77 million/€61 million) would need to be found from somewhere for the overall funding cake in 2017-21 not to shrink.

It is possible that Lottery funding may make up some of this potential shortfall.

Just in case it doesn’t, however, the chancellor has stepped into the breach, or so it would appear, with a promise to contribute a handy increment of £46 million ($69 million/€65 million) or thereabouts.

UK Sports Minister Tracey Crouch reacted to the chancellor’s announcement by saying that the “settlement recognises the wider value of sport in society and how it plays an important role in boosting the economy".

She added: “The increase in funding will support our elite athletes in the run-up to the Tokyo 2020 Olympic and Paralympic Games, grow the grass roots to get more people involved in sport and promote clean sport in the UK and beyond”.

Meanwhile, UK Anti-Doping (UKAD) looks set to receive an increase in funding of £400,000 ($605,000/€570,000) or seven per cent of its budget.

David Kenworthy, the UKAD chairman, had warned that the organisation would be in "jeopardy" if its funding was slashed.

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September 2015: UK Sport warns on possible impact of British Government’s Comprehensive Spending Review
March 2015: UK Sport "no compromise" to be softened following public review