Make election manifestoes a legally-binding contract with the electorate.
Background
Introduce an element of compulsion to ensure that manifestoes contain only clear and unambiguous promises which must be implemented exactly as stated and in full - with substantial financial penalties for failure to do so and possibly custodial sentences for deliberate non-fulfilment or dishonesty.
Additional details
We are heartily sick of manifestoes that contain promises which the party concerned either has no intention of keeping, or which include deliberately misleading statements about what is actually intended.
Source: UK Government & Parliament Petitions service. Petition ID: 709584.