She marched past energy firm Cuadrilla's exploratory oil drilling site in West Sussex, which has been the focal point of protests.
Up to 1000 protesters are due to join the six-day Reclaim the Power Camp on the outskirts of the village to highlight opposition to the controversial extraction method.
Dame Vivienne called for a public debate on fracking, saying she believed it could store up trouble financially and environmentally.
She said: "There has been no debate. They are trying to rush this thing through, for what?"
David Cameron has insisted the whole country should accept fracking, claiming it will attract "real public support" when the benefits are explained.