Well………
If it's Salary and you've got no choice then, assuming a standard tax code and no pension contribution. Takehome should be ~ £4200 (ish)*
Earning 75k as a Salary it's well worth looking at tax options and using dividend income as an alternative.
Net cost to a company for a Salary of 75k is likely to be around £84000 with Emp NI. So you could negotiate a long term contract and supply your services as a business. Set a Ltd company, register for VAT etc. it may be a bit of a pain but other benefits are you can expence travel, lunch, etc.
Say the business invoices 80,000+VAT a year for your services.
Take a salary of 15000
Expences of 5000
Net P&L ~60000
So take off CT & Tax on divs and add back in you 15k a year salary your takehome is going to be ~ £5000 ish*
*This is all guestimated and could be hugely wrong