[6] During the period between the announcement of the engagement of Prince William and Catherine Middleton in 2010 and the Diamond Jubilee of Elizabeth II in 2012, the group's supporters increased from around 9,000 to around 30,000,[7] with around 500 new members being gained at the time of the 2011 Royal Wedding.

"[9] Following the death of Elizabeth II, Republic briefly suspended public comments out of respect for the late Queen, and then returned to campaigning following the proclamation of accession of Charles III.

In this modern world of highly connected citizens and networks that circumvent traditional sources of information continued secrecy will gradually erode public trust in the institution.

In May 2007, Republic persuaded Brian Iddon MP to table an early day motion about the lack of transparency in the Duchy of Cornwall's accounts.

[19] In 2013, lobbying by Republic resulted in William Nye, Prince Charles's private secretary, appearing before the Public Accounts Committee to explain the Duchy's tax arrangements.

In response, Republic made a freedom of information request for VisitBritain documents which indicated that royal weddings had in the past had a negative effect on tourism.

[7] Republic held an alternative street party in London at the Royal Wedding, "celebrating democracy and people power rather than inherited privilege", along with other events across the UK's major cities.

[29][30][31] In March 2016, Smith filed a formal report to the police, requesting an investigation into allegations that Prince Andrew, Duke of York had caused damaged to sensor-operated gates in Windsor Great Park by forcing them open in his Range Rover to avoid going an extra mile on his way home.

[35] In the letter, which was sent from Republic's London address,[36] the signatories expressed "upset and anger" in the wake of a ruling (made the day before by the New York judge Lewis A. Kaplan) that Prince Andrew must face a civil lawsuit in the U.S. for alleged sexual assault brought by Virginia Giuffre, and they argued that it was "untenable" for the Duke of York to retain his positions in the armed forces.

[35] Later in the day,[34][35] Prince Andrew's military affiliations and royal patronages were returned to the Queen, and it was announced that he would defend the lawsuit as a "private citizen".

In response to these Republic asked the Metropolitan Police to reopen its investigations into the allegations and called on King Charles to make a public statement.

[38] Prior to the Coronation of Charles III and Camilla on 6 May 2023, Republic announced plans to hold demonstrations at Parliament Square in London against the ceremony, citing opposition to the extravagance of the event amidst the UK cost of living crisis.