Sirius, I get what you are saying - BUT - immigration is not what is bringing down the NHS. We know that migrant use of the NHS is actually a very small percentage of the cost.
British citizenship (born or naturalised) does not give bill free use of the NHS. The NHS was set up a long time ago, to be financed by paying all your working taxes to the UK, but no checks are made on that.
Under the NHS changes that saw this IHS come in, we saw health care paid for by the UK linked to those in receipt of the UK state pension for the first time. Suddenly some of those who had been having their medical care paid for by the UK taxpayers under the S1 system as they had British citizenship, found that had now ended in 2015 and they now needed insurance to pay their own medical bills.
At the same time, we also saw the end of piggybacking a UK state pension from a spouse and now a UK state pension is based solely on your own contributions.
Illegal use of the NHS is costing huge money. And they should be cracking down on that. Not once, during either of my pregnancies, did anyone ask to see that I had legal documentation to be using the NHS at all. They should have checked my documents.
The NHS has been very easy to abuse and not just by foreign nationals. As for illegal use of the NHS, NHS records are just some of the records that are used by the Home Office to locate overstayers/illegals and deport them, refuse visas because of unpaid NHS bills etc.
They didn't need to see your documents for your first birth, they should have used the HMRC Real Time system that was brought in to find fraudsters and seen that you were working in the UK. For the second birth, the Immigration Act 2014 was in and UKVI would have marked the NHS SPINE system with a green banner on your name to ensure you are not billed.
That 2014 law means that the NHS trusts are now fined if their staff are too lazy to check and bill, as we have seen in the past. This means that NHS trust now lose out twice if their staff are too lazy. e.g. not only do their budget have to fund the cost of that treatment that they should have billed for as they are now fined too. If they check, they either claimed that money back for the cost of that treatment from all the IHS payments held in a central fund, or they bill that person and add 50% if there is no insurance to pay and their trust keeps all that money.
I get that immigrants are an easy target. No native British citizen is going to contest that immigrants should be allowed exclusive use of the NHS. And no voting rights mean we are silenced.
The IHS is about contributing something before the NHS is used and we didn't get to vote on that system either. It was what the MPs and Lords chose for the NHS, instead of the having to pass a medical that other countries require for a visa. However that's not to say that it won't be medicals instead of the IHS at a later date, as UK laws allow parliament to change laws they don't like anymore.