No, provided you are not intending to make the contents of the communication available to a third party. If you are you will need the consent of the person you are recording.
The following is a verbatim extract from "Explanatory Guide to the Self Provision Licence (SPL) and the Telecommunications Services Licence (TSL)":
"18. The condition provides that you should make every reasonable effort to inform all parties to a call that it may or will be recorded, silently monitored or intruded into. The particular means by which you choose to do this are not specified in the condition. Acceptable options, depending on circumstances, might include warning tones, pre-recorded messages, spoken warnings by the operator or written warnings included in publicity material, telephone directories, contracts, terms of business, staff notices, etc. It may not always be possible to warn first-time callers with whom you have had no previous contact but what is important is that you have a systematic procedure in place which provides the necessary information wherever this is a realistic possibility."