June 28 (Reuters) - London"s FTSE 100 marked its worst day in over a week on Monday, dragged down by losses in heavyweight energy and financial stocks, while Burberry slipped to the bottom of the index after the resignation of its chief executive. The blue-chip index (.FTSE) fell 0.9%, with Burberry (BRBY.L) tumbling 8.7% after the luxury group said its CEO Marco Gobbetti would step down to take up another opportunity in his native Italy. read more . Oil majors BP (BP.L) and Royal Dutch Shell (RDSa.L) fell 3.2% and 3.3% respectively, tracking weaker crude. Life insurers (.FTNMX303010) and banks (.FTNMX301010) fell over 1.7% and were among the biggest drags to the index. Travel-related stocks (.FTNMX405010) fell 3.4% with Wizz Air (WIZZ.L), Ryanair Holdings , British Airways-owner IAG (ICAG.L) and Easyjet (EZJ.L) falling between 3.8% and 5.6% after a report said Germany would attempt to ban British travellers from the European Union regardless of whether or not they have had a COVID-19 vaccine. read more "Summer 2021 was supposed to bring salvation for the UK travel sector as lockdowns were lifted and arms were jabbed; instead it has brought more confusion and a dawning realisation that a big money booking boost isn"t on the cards," said Danni Hewson, financial analyst at AJ Bell. However, Prime Minister Boris Johnson said Britain is on course to be able to lift most remaining COVID-19 restrictions on July 19. read more The FTSE 100 has gained 0.9% so far in June and is on track for a fifth straight monthly gain on expectations of a stronger economic recovery on the back of accelerating vaccine rollouts and ultra-loose monetary policies. However, the FTSE 250 is set for its first monthly drop since January as Britain delayed its complete reopening on concerns over a recent spike in COVID-19 infections. The domestically focused mid-cap FTSE 250 index (.FTMC) declined 0.5%. Among stocks, Greggs (GRG.L) rose 2.9% after the British bakery and fast-food chain said sales recovery was stronger than anticipated, adding that a sustained recovery from the COVID-19 pandemic could boost its annual profit. read more Reporting by Devik Jain in Bengaluru; Editing by Subhranshu Sahu Our Standards: The Thomson Reuters Trust Principles.