The Government needs to go further than this if they want to maintain the vibrancy of town centre High Streets.
They should give cash to councils that make their High Street parking areas free for people that spend on the High Street. The cuts that central Government has made to local councils has forced them to charge for every service and try to make their own money in every way they can. This affects people's choice of whether they go to the High Street, pay to park and always have an eye in the clock, concerned about a parking ticket. The contrast is out of town, free parking, plenty of time and often more choice.
To compete, High Street have to start with the parking issue. If you provide free parking for those who spend a certain amount in the town, maybe get your parking attendants to be a little more human and sort out the staff parking situations then it will go a long way to redressing the amount of floor space approved in town centres, as shoppers and retailers will want to return.