The right to vote for a political party of your choice is an important and democratic right. No one has the right to tell you who to vote for. You may get canvassers telling you why they think you should vote for their party, though this is normal practice. However, offerings of money or threats of violence is not normal practice and must be reported to the police.
It is an offence to offer money or gifts in return for voting for a particular party or candidate and to offer undue force/threats/violence to compel or refrain a person from voting for a particular party or candidate. Both these offences can carry a term of imprisonment. You must report any such instances to your local police station.