<p>French papers react to Crimea's "illegitimate" vote to join Russia and warn the West must stand firm in the face of Russian provocation.</p><br />Meanwhile, former president Nicolas Sarkozy remains the favourite among UMP voters to run again in 2017. And Paris' smog crisis is having an effect on Sunday's mayoral election.<br /><br />Visit our website:<br />http://www.france24.com<br /><br />Like us on Facebook:<br />https://www.facebook.com/FRANCE24.English<br /><br />Follow us on Twitter:<br />https://twitter.com/France24_en
