2011年，蕭凌志成為社民黨喺漢堡州選舉嘅主要候選人，社民黨以48.3%的得票率贏得漢堡議會121個席位入面嘅62個。2011年3月11號，佢喺當選為漢堡市長號三天之後辭去聯邦議院議員嘅職務。
In 2011, he became the SPD's main candidate in the Hamburg state election, winning 62 of the 121 seats in the Hamburg parliament with 48.3% of the vote. On 11 March 2011, he resigned as a member of the Bundestag three days after his election as mayor of Hamburg.