(For a Reuters live blog on U.S., UK and European stock markets, click LIVE/ or type LIVE/ in a news window) * FTSE 100 down 0.4%, FTSE 250 off 0.5% Nov 30 (Reuters) - London shares fell on Monday as fears of a no-deal Brexit as well as the economic damage from the COVID-19 pandemic knocked back sentiment at the end of the best month for the FTSE 100 in more than three decades. The blue-chip FTSE 100 was down 0.4% by 0804 GMT following a rally of more than 13% this month that was sparked by hopes of a working coronavirus vaccine before the end of the year. The domestically-focussed FTSE 250, considered a barometer for Brexit sentiment, lost 0.5%, but was still set for its biggest monthly percentage jump since the global financial crisis in 2009. Britain and the European Union are heading into a “very significant” week, British foreign minister Dominic Raab said on Sunday, as talks over a trade deal enter their final days with serious differences yet to be resolved. BP Plc and Royal Dutch Shell Plc were the biggest drags on the commodity-heavy FTSE 100 as oil prices slipped ahead of a meeting of producer group OPEC+ to decide whether to extend large output cuts to balance global markets. (Reporting by Shivani Kumaresan in Bengaluru; Editing by Saumyadeb Chakrabarty)