Before we get to that, taxes (in the United States of America, I rarely comment on the politics of countries not my own.) If you take away exemptions and loopholes and tax havens and credits and the downright screwy way we treat capital gains one fact becomes apparent about income tax: Everybody pays the same.
When all of the exploits and such are taken away and you're just left with, "This is the income tax upon which all of that other stuff is based," the fact of the matter is that everyone, from someone who earns no money to whoever earned the most (excluding capital gains because it's taxed a different way) everyone pays the same rate.
The differences come in because X% of 0 is 0. Doesn't really matter how big X is so long as it's finite. (if X is infinity then break out the calculus.) If someone earns zero dollars in the top bracket then that zero dollars is taxed at the same rate as someone who did earn money. It's just regardless of the rate the person who earns zero dollars in that range won't have to pay anything at that rate X% of zero is always zero.
Thus, at it's most basic, before we get into all the junk thrown on top, how you're taxed never changes regardless of how much or little you make. This kind of thing has a lot going for it. For one thing it means you don't ever run into a situation where earning more money results in you keeping less. For another thing it means that you can instantly shut down any argument on, "How come they only pay [whatever] in income taxes," by pointing out that the person asking the question payed the exact same amount on that level of their income. The envy that the rich have for the poor with respect to taxes becomes absurd once one realizes that they actually pay the same rate. (Except for capital gains, and loopholes, and tax havens, and various other ways the rich are able to pay less than the poor in taxes.)
I bring this up because were it up to me basic aid (as in on necessities, not disaster relief and such) would be treated the exact same way. Everyone gets the same.
Everyone gets food-stamps (now they come on cards) enough to afford to keep fed. Everyone gets housing aid enough to give them adequate shelter (this includes heating), everyone gets access to medical care (probably via everyone getting on something like Medicare or Medicade.) Everyone gets access to education, so, so forth.
One thing that this does is it eliminates layers upon layers of bureaucracy that are currently used to determine who is bad of enough to get help. Everyone gets the same so there's no need to check to see if you're worthy. You just have the food aid added to your food card every month, the other aid added to the other cards, and get a, "I've got health insurance through the government" card and so forth.
It also eliminates all of the work (paperwork, hoops to jump through, so on) that people need to do to get aid.
But another thing that it does is it puts a serious dent in the argument from envy. Yes, the "undeserving poor" (a category that doesn't exist except in the minds of certain people) might be getting this stuff for free without having to work for it, but so too are you.
And it eliminates a problem that people who are on the edges face, which is that there are places where making a little bit more money will mean you no longer qualify for aid, which will end up leaving you worse off. So it's in your best interest to not make more money. Now I've never met someone who decided not to make more money on those grounds, but I have met someone who was seriously screwed over because he made two dollars too much (two fracking dollars) to be considered poor enough to get aid, which ended up leaving him poorer than if he just hadn't worked that year and thus qualified for aid. If the aid never goes away then you never have that problem.
If we give everyone enough to be able to live with the basic necessities then we simplify the process of figuring out who to give to (everyone gets it), we eliminate the thresholds where incentives become perverse (if you make more you'll be off aid and thus worse off), we at the very least dent the argument from envy, we make it easier for people who need help to get it (because it comes to them automatically rather than depending on them doing thing after thing after thing to fight for it), and we loose very little.
The problem is, of course, that it costs more. Consider food stamps alone, you'd have more than six times as many people on them. Now some of the cost of that increase can be taken away by removing all of the work to determine who needs them, but I very much doubt it would be enough to take away all of that extra cost. For fully funding it I think new revenue would be needed, which works fine for me because I think our tax code could use some serious reworking. We need more tax brackets and the top marginal tax rate needs to be a lot higher. Also taxing capital gains at a lower rate than the money people actually had to work for is absurd.
So the plan would involve higher taxes for some, but it would also mean that no one would ever have to fear being without the basic necessities because everyone, even the ones paying the higher taxes, would be given enough to take care of those by the government. Whether or not someone like Bill Gates would use his foodstamps, were he given them, is an interesting question. But the point is that by giving them to everyone you make sure that everyone who needs them gets them (something our current system doesn't accomplish) and you make sure that there's never a perverse incentive to make less money in order to stay on aid.
The same with giving everyone medical insurance, or everyone money to be spent on housing. The same with all necessities.