Here's Jonathan Portes saying some of this on Sky News. I believe he is currently Professor of Economics and Public Policy at King's College London, but was previously a civil servant, Chief Economist and Director of Welfare to Work at the DWP, commenting on a snapshot in time perspective on welfare costs. Factually, he isn't wrong depending on what figures you use for welfare. Strip out pensions and look just at working age benefits, and things might look a bit rosier. Add pensions and health-related benefits, and the picture changes again, because an ageing population pushes costs and the direction of travel for those costs irrespective of who's in power.
I don't know what you mean by a snapshot in time perspective on welfare costs? He's comparing welfare spending as a percentage of national income across 5 decades and pointing out that it has remained almost totally unchanged according to the government's own statistics (which compare like for like to the extent that that's possible). As far as I'm aware these overall statistics include state pensions and health related benefits if you mean disability benefits but not the NHS. And yes, while some of these individual areas of welfare spending have gone up (notably pension spending massively), because there have been cuts to other areas of welfare, there has been no overall rise. So it's totally misleading to say that welfare spending is "ballooning" when it isn't even rising.
The stat is also doing an awful lot of heavy lifting. All it really tells you is where welfare spending is today. It tells you nothing about whether that level is appropriate, affordable or sustainable, where the money will come from, how efficiently it's being spent, the demographics, how fair the financial burden to pay for it all will be spread and so on. It certainly doesn't tell you whether we are heading towards a cliff edge or if whoever is in power has the skills to steer us back onto a financially sustainable path
It tells us a lot more than where welfare spending is today - it tells us that it is today more or less exactly where it has been for 5 decades and that the government have, rightly or wrongly, put huge efforts into keeping it that way. I haven't argued anything beyond pointing out that the repeated assertions that it's spiralling are false. That the need for greater welfare spending is another matter.
Sustainability is about addressing known and predictable long term challenges before they become crises, not waiting until you are forced to ask, "Where is the money going to come from?" Which is currently where we are with the state pension. The birth rate started falling c1965. Successive administrations have had decades to plan and deal with it but they chose to kick the can down the road rather than make the medium and long term changes needed to keep it sustainable and reduce dependency on the state.
Successive governments have been addressing the situation - they've done all sorts of things eg, they've increased the pension age, enforced laws to ensure employers contribute higher amounts to pensions, encouraged the provision of greater private provision. Whether or not it's to anyone's satisfaction is another matter but they've made and are continuing to make many efforts to address the situation. They've also reduced various areas of working age welfare so more can be spent on pensions.
As for Novara Media, that bastion of neutrality... It's openly on the left, so it's hardly surprising that they selected a carefully curated clip.
I know nothing about NovaraMedia but the clip appears to be an unedited segment from Sky News in which an economic expert who has worked for the government corrects the incorrect assertion that welfare costs are spiralling. I think it stands alone as a source regardless of who posted it.
TLDR: You may not like the use of the word "ballooning", but welfare spending is rising and, on the current trajectory, it is not sustainable. A snapshot taken out of context is no substitute for robust, sustainable medium and long term planning.
You acknowledged yourself that it isn't ballooning where you said that Factually, he isn't wrong depending on what figures you use for welfare. Given you haven't provided sources for any alternative comparisons it's hard to determine the basis on which you're still trying to argue that spending is in fact ballooning. I will look at them if you have them though? The source I provided isn't any sort of snapshot taken out of context. It's an economic expert who has studied the government data over the last 5 decades and is confidently asserting that they show that welfare spending is not spiralling.
Where we maybe agree is that there is and will continue to be rising pressure for more welfare spending and yes, that is a massive problem that needs to be solved. We won't solve it by repeatedly misrepresenting it though as the government seems insistent on doing.