Christopher Graham's warning comes as the Information Commissioner's Office issues updated guidance for parties and candidates covering a range of communications channels including direct mail, emails, text messages, phone calling and automated phone calls.
Speaking at the DMA Data Protection Compliance Conference this morning, Graham urged the parties to stick to the guidance, highlighting their "disappointing collective track record".
The ICO has previously taken regulatory action against all three main parties and the SNP. It recently served an enforcement notice on the Labour Party after it made unsolicited automated marketing calls without consent to almost half a million individuals.
The ICO has summarised its guidance for parties in the following table:
| Communication method | In summary you may use this method to promote a party or candidate... |
| Post addressed to particular individuals | …unless the individual has asked you not to write to them or not to send them marketing material by post. In addition, s91 of the Representation of the People Act 1983 gives a candidate at a parliamentary election the right to send an election address by post. This specific right applies even if the individual has asked you not to contact them. |
| Email/text and other messages to mobile phones/voicemail | …where the individual has consented to contact of that sort from you for those purposes. |
| Fax | …where the individual has consented to contact of that sort from you for those purposes. |
| Phone calls | …unless you have grounds for believing the individual would not want you to contact them such as Telephone Preference Service (TPS) registration. |
| Automated phone calls | …where the individual has consented to contact of that sort from you for those purposes. |
| AND in every case | …you must normally identify yourself in the communication and provide contact details to allow individuals to contact you and easily opt out of unwanted direct marketing. The Representation of the People Act 1983 also requires specific details to appear on election publications. |