Dr 7000 Salaries with gross pay Dr 7006 with ERS NI Cr Net Pay 2220 with net salaries Cr PAYE/NI 2210 with amount due to HMRC.
When you write the cheque, you enter a Bank payment to 2210 to negate the amount credited in the journal above, and the same with the salaries, when you pay them you debit 2220 with the same amount as in the journal above (assuming there are no under or overpayments).
There is no need to enter Tax and NI separately in the posting of the payment to HMRC.