Is a regional corporate tax rate achieveable and practicable?

Mick’s thread yesterday highlighted how the twin track nature of the UK’s economic development. In the present talks the issue of boosting the economy by introducing a lower regional corporate tax rate for Northern Ireland has been suggested but rejected by government. However, what is good for NI could be equally so for other under-performing parts of the UK. Should the proposals be broadened to include other regions? Does expanding it out make it more sellable/achieveable as a policy goal? It would be hard for Northern MP’s to argue against and would the Tories want to engage in a public fight against a tax cut for business? What are the practical barriers to introducing regional corporate tax rates within a unitary state? Would it just end up as book movements and more lucrative work for tax lawyers? In terms of the global economy, the Republic of Ireland’s experience is that it leads to real growth and some book movements. Would it produce the same results within a country?