Seems like a C&P of my recent post from the other kitten breeding thread would be useful here as well.......
The RSPCA published a Cat Crisis Report in 2014 which I would recommend reading Niclou. There's a download link towards the bottom of this page.
Here's a few excerpts which I think are especially relevant:
"The cat population in the UK has reached crisis point. The numbers of cats entering the RSPCA increased by eight percent in the period 2010–2012, from 29,269 to 31,556... Conversely, in the same period, the number of new homes that took in cats declined by 10 percent, but not as a result of reduced rehoming activity."
"Acquiring a cat spontaneously (i.e. those who acquire a kitten from a
friend or family member whose cat has had a litter of kittens) correlates strongly with not neutering (50 percent less likely to neuter). Those who do not neuter are also likely to have friends and family who do not neuter."
"The ‘one litter’ myth is further reinforced by owners applying human emotions to their cats, e.g. “she’ll make a great mum/I don’t think it’s fair to deny her the right to motherhood”."
"Having a litter serves as a trigger for many to neuter – with the reality of having to look after, pay for the care of and part with the kittens, not living up to what cat owners had imagined. Despite this, 21 percent of cats that had a first litter will have a second litter and seven percent have a third litter or more. The more litters a cat has, the greater the chances of her – and the kittens – ending up in rescue."
As of June this year the RSPCA had over 800 kittens needing homes across their centres/branches. Also as of June this years, Cats Protection had taken in over 3,000 kittens nationally, with 1,600 of those being cared for in their centres at the time this article was published. In 2016 alone CP rehomed over 14,500 kittens.
That's just two of the big name charities. The same story (rescues full to capacity during kitten season) is repeated over and over across the country, in rescues large and small. However much you fancy breeding a moggie litter as a nice, fun experience for your children the fact is that doing so is not only putting your cat at risk or injury/death/disease but it categorically will be contributing the current overpopulation crisis, whether you want to accept it or not.