"if the coalition really wanted to reverse the trend towards short-term thinking, it would change the rules on the tax-deductibility of interest since the current rules encourage companies to load up with debt to reduce their tax bills"
At first I was confused. After all, the fact that interest is tax deductible simply reduces the cost of servicing debt. The full amount of the interest payable still has to be funded out of cashflow. If the business is not generating sufficient cash to cover the interest cost the tax relief is irrelevant. It simply reduces the corporation tax payable at a later date - and if the business is loss making there is no tax payable anyway.
There are also situations where the borrowings are drawn from a group company which will not pay tax on the interest earned (eg: if located in a tax haven). So the group as a whole simply reduces it's UK tax bill by reference to the intra-group interest payable to the offshore group company. So far as I can recall the 'loan relationship' rules do not prevent this type of mismatch.