LONDON- Prime Minister Gordon Brown said Britain was sending Royal Navy warships to rescue Britons stranded by the volcanic ash cloud. Brown added the aircraft carrier HMS Ark Royal and HMS Ocean would be sent across the English Channel. A third ship may also be deployed. He said Britain was speaking with Spanish authorities to see whether Britons stranded overseas could be flown there and then taken home by boat or bus. Air space in countries including Britain, France, Germany and The Netherlands home to Europe's largest airports have been closed for days, stranding millions of people. Meanwhile, the aviation industry sharply criticized European governments on Monday for their handling of airport closures, saying there was "no coordination and no leadership" in the volcanic ash crisis that shut down European airports for a fifth straight day. Some smaller airports reopened, and European officials had hoped that flights could return to about 50 percent of normal on Monday if the skies were clearing. But authorities in Britain, France, Germany and The Netherlands home to three of Europe's largest airports said their air space was still closed. Britain said it was keeping flight restrictions on through until at least early Tuesday, while Italy briefly lifted restrictions in the north then quickly closed again Monday after conditions worsened. Austrian authorities reopened the country's airspace, though many flights there remain canceled, and Stockholm's Arlanda Airport was reopening for limited air traffic. Finland opened its Tampere and Turku airports but kept its main airport in Helsinki shut, and most Norwegian airspace reopened Sunday evening.