I definitely wouldn't, certainly not in the UK. If you're caught out, it's grounds for dismissal. And the vast majority of employers will seek your P45 and pay

I definitely wouldn't, certainly not in the UK. If you're caught out, it's grounds for dismissal. And the vast majority of employers will seek your P45 and pay slips from your current job. However, it is perfectly reasonable to expect an uptick on moving: this is to compensate you for the risk and overheads of moving. Most employers will expect to have to pay you more.