Self-certification is available with lots of lenders still and it basically means that they will not verify the income figure you put down. However ALL companies have reasonability checks in place so you have to ask yourself would anyone doing your job earn £50k?

Mortgage lenders have income multiples to protect clients as much as themselves, i sincerely hope you're not seriously considering borrowing 150k on your salary...just as an idea most lenders standard rate is around 6.5% thats £815pcm mortgage payment, add council tax and your salary is gone