Are National Insurance contributions deducted before tax?

[wrongsideof40]

Complete newbie question, but I can't seem to find the answer...

I'm a sole trader, and have the dubious pleasure of filling in a self-assessment form, soon. I want to pay Class 2 NICs so my question is: For tax purposes, are the contributions deducted before paying tax, or not?
Also, who and how do I inform that I want to pay them?

Thanks - Martin

[JRG]

All NICs are payable in addition to income tax. Class 2 NICs are payable at £2.95 per week on profits exceeding £6,205 for this tax year.

[wrongsideof40]

Thanks for that, JRC. Year 1 profits won't get near 6K but I want to keep my NI payments up for State Pension purposes