Not quite 2 months in arrear but erratic payments

Rent Arrears

I have had a tenant for 20 months on a 6 month AST. Until 6 months ago she was my best tenant but has been erratic with her payments since Sept 08 and was 2 months in arrears on the 21st Feb 09.

I issued a Sec 8 notice immediately but she has made a small payment since then, making the arrears £866 (1.76 months).

She will no longer return my calls or pay the weekly amount we agreed to try keep her rent payments regular (and pay off the arrears over a 12 month time scale).

Can I still issue court proceedings using the Sec8 notice?

I do not want to evict her but cannot get he to return my calls and do want to wait for another full months arrears to accrue until I can issue proceedings.

Please advise.

Richard