Police fired tear gas to clear the road outside President Nicolas Sarkozy's office yesterday after protesting farmers briefly blocked the Élysée Presidential Palace and spread hay in front of the entrance.

Protestors bundled two bales out of a van as it drove slowly past the Élysée in a pre-dawn raid, and scattered the hay across the road before police reinforcements arrived.

Around 70 protesters were later cleared from the main road and forced out down a side street after police fired tear gas.

Damien Gressin, head of the Young Farmers' Association, said some of the demonstrators were arrested.

Average revenue per farm in France fell 34 per cent in 2009, the agriculture ministry said earlier this week, with crop farmers' slumping by almost half.

The falls were due to a rise in the cost of fertiliser and a drop in the price of cereals from 2008 levels.

"Nicolas Sarkozy is not properly defending agriculture and is letting the United States and India pursue a strategy of economic power," the Young Farmers' Association said in a statement distributed to journalists.