A declaration urging Christians to vote in line with their conscience and beliefs in the general election has racked up more than 20,000 signatories in less than 10 days.

The Westminster 2010 Declaration of Christian Conscience has also attracted 2,000 Facebook fans since it was launched on Easter Sunday.

Signatories include former Archbishop of Canterbury Lord Carey, the head of the Catholic Church in Scotland Cardinal Keith O’Brien, and General Director of the Evangelical Alliance Steve Clifford.

The document speaks in support of marriage and the freedom to live according to religious beliefs, and expresses opposition to assisted suicide. It is also a rallying call to Christians to stand up for vulnerable people.

Although parliamentary candidates are not being asked to sign the declaration itself, they are being asked to instead pledge to “respect, uphold and protect the right of Christians to hold and express Christian beliefs and act according to Christian conscience”.

The declaration is in part a response to recent cases of Christians experiencing discrimination in the workplace.

It has grown to be bigger than all but six of the nearly 5,000 public petitions on the Downing Street website.

With four million regular churchgoers in Britain, and on average 6,000 per constituency, signatories are hoping the declaration will play a role in impacting who is elected, particularly in marginal seats.