The mother of five has been in prison for seven years and will have her final appeal heard this year.
The protest, organised by the British Pakistani Christian Association (BPCA) saw the group march from the Pakistan Embassy to Downing Street where they handed in a petition with around 20,000 signatures.
The petition calls for Pakistan to ensure Asia Bibi has a fair trial and that she is protected from harm in a nation that despises her because of her faith.
Speaking to Premier, Wilson Chowdhry from the BPCA said: "Major donors such as the UK and the USA need to start to use their substantial foreign aid budgets to Pakistan as leverage for better human rights - with real conviction.
"Britain's official policy involves tackling poverty by generating sustainable growth and employment, as well as focusing on education and health, all worthy goals.
"Some of the poorest Pakistani citizens are Christians, and unfortunately they are typically kept there by a combination of debt-slavery and direct and systematic religious oppression, frequently including systematic sex slavery and targeting of Christian girls and women for kidnap, rape, forced conversion and marriage.
"Britain and the US simply must use their aid budget to remove this social disparity."
Similar protests are taking place in Glasgow, Manchester and Birmingham later this month.