most of the whole host of negative impacts depend heavily on the level that it's set and what other benefits are withdrawn, which there's very little agreement over. Low end BI with aggressive removal of other means tested subsidies generally leaves poor people looking for work much poorer; high end BI is leaves most taxpayers much poorer, whilst potentially seeing , much of the increase to people on low incomes swallowed up in increased rent. But more generally:

- massive distortion of low-end wages, particularly for unpleasant, useful but not particularly revenue-generating jobs such as cleaning. Further outsourcing of manufacturing work for the same reason might be considered a negative aspect by some (especially people with moderate-to high skills related to that manufacturing)

- massive skewing of wage payments away from younger people in many competitive areas of employment, because now that the taxpayer will cover living costs and assuming removal of minimum wages there's absolutely no reason to pay trainees, apprentices (or the likes of runners desperate to make it in television) any non-trivial sum until they've spend a long time "proving their worth".

- regional cost-of-living differences and a guaranteed permanent income encourage former job-seekers to relocate to areas where their prospect of getting a job is minimal. This is further exacerbated if better-targeted housing benefit payments and social housing are removed from the equation.

- depending on the level of BI entitlement children get they're either likely to become a lucrative income source or unaffordable in many areas, especially for single parents.

- a surprising amount of BI revenue will be captured by low-end rents, and other costs that people with more cash to spend at the bottom of the pyramid can't avoid. A surprising amount of BI costs will be funded by the productive

- non-citizens are inevitably going to be heavily penalised (otherwise the country becomes an migrant magnet)

- many advocates use BI as an excuse to push for middle-class squeezing flattening of the tax system, withdrawal of education and health subsidies etc.

- the cost of paying people who would really rather not work almost certainly vastly exceeds the cost of paying wages to people whose job it is to kick people who would really rather not work off benefit programmes. Throw in the fact that people who never had any intention of claiming benefits are now entitled to them.

Like every other reform to the tax or benefit system there are a whole host of winners and losers (including people you probably don't want to be winners like "slum landlords" and the indolent, and people you probably don't want to be losers like the owners of the neighbourhood cleaning firm and hardworking immigrants). It's about as far from the proverbial silver bullet as imaginable: it's reforming existing incentives that have (for better or worse) been tested and debated for decades with a blunt instrument.