Chaired by Chan Po-ying, wife of Leung Kwok-hung, it positions itself as the radical wing of the pro-democracy camp and stresses on "street actions" and "parliamentary struggles".

The party suffered a sharp decline in the 2012 Legislative Council election but resumed a cooperative relationship with the People Power in the issues such as filibustering in the legislature and street activisms.

Facing the rise of localism, the two parties formed an electoral coalition in the 2016 Legislative Council election which received seven per cent of the vote with Leung Kwok-hung being re-elected.

It positions itself as a social democratic party[1] and believes that a just society can be achieved by redistribution of wealth, economic interventionism and direct democracy.

At the opening of an exhibition at the Museum of History on 2 March 2011, Steve Wong Chun-kit, member of the League of Social Democrats rushed at Donald Tsang.

Tsang denounced the protest, saying that violence was unacceptable in Hong Kong, where civilised behaviour and the rule of law were fundamental values.

[4] Leung Kwok-hung threw a cloud-shaped cushion at Financial Secretary John Tsang during his budget report in the Legislative Council on 27 February 2013 to demand for a universal retirement protection scheme.

[5] At a political forum on 7 December 2013, one member was captured by the media throwing a Lufsig, a cuddly toy wolf at CY Leung.

In Kowloon East Andrew To Kwan-hang has accused the Democratic Party of wrongly backing the government's move to privatise the Link Reit Investment Trust, thus paving the way for hefty rent rises in public housing commercial and parking facilities.

The claim of by-election as referendum expectedly received serve attacks from the Beijing government and the pro-Beijing camp in Hong Kong as unconstitutional.

In November 2010, Wong Yuk-man's protege Edward Yum led a no-confidence motion against To which was defeated by 111 to 170 at an extraordinary general party meeting.

[15][16] Wong and Chan formed the People Power with other defected members and radical groups which aimed at sniping Democratic Party in the upcoming 2011 District Council elections.

Two days later, Andrew To resigned as chairman, to take responsibility for the loss, but pledged not to alter the LSD's ideology for the sake of winning elections.

The alliance won two seats in total with sole League legislator Leung Kwok-hung and People Power's Ray Chan being re-elected in the New Territories East.

In spite of this, Leung Kwok-hung was narrowly defeated in his bid to unseat incumbent lawmaker Starry Lee in the To Kwa Wan North in the Kowloon City District Council.

[23] Chan Po-ying, Leung Kwok-hung's wife, was elected as the LSD's new chairperson during a special meeting on 25 July 2021, replacing Raphael Wong.

Dickson Chau was also elected as vice chairman (external affairs), replacing Leung Kwok-hung, who was jailed for his role in the 2019 protests.