Election campaign launches by Labour and the Liberal Democrats were overshadowed today by the death of Baroness Thatcher.

As the news emerged, aides to Ed Miliband signalled that the party would be putting activities ahead of key local polls next month on hold.

Lib Dem leader Nick Clegg also broke off from a visit in the west country to add his tribute, while David Cameron has cut short an official trip to Spain and cancelled a regional visit tomorrow.

There is speculation that the Tory campaign launch due next week could also be delayed.

Before the death was announced, Mr Miliband told an audience in Ipswich that Labour would protect high streets.

He said: "Too many councils are finding that they don't have the real power to stand up for local people. But that is what politics is supposed to be about: standing up for those without power and giving power to them. Currently if a bank branch closes down, there's nothing a council can do if a payday loan shop wants to move in and open up in the same place. Even if there's another lender next door. That can't be right."

The party plans to create an additional umbrella planning class that would let local authorities put some premises in a separate category. The move would allow councils to then block applications that meant a change of use for a property.

Mr Miliband also accused the Tories of "nasty divisive" politics for trying to link the case of childkiller Mick Philpott to the ongoing row over welfare reforms.

Meanwhile, Mr Clegg used his speech in Cornwall to insist only his party offered a different approach.

"Despite all their stated differences, a vote for Labour or the Tories will be a vote for the same thing. Their record in local government shows that, even when millions of families are feeling the pinch, they'll both squander taxpayers' money on waste, inefficiency and their own vanity projects," he added.