Representatives of the arms industry and UK government are to speak at a seminar that extols the sale of arms to repressive regimes in the Middle East.
Christian communities in the UK are expected to take part in a Day of Prayer four weeks today, when one of the world's largest arms fairs opens in London.
Campaigners will attned the Spirit of Summer Fair in London this weekend to highlight the fact that the owners, Clarion Events, are also involved in the arms trade.
There has been an outraged response to news that the UK has licensed sales of crowd control weapons to regimes that are violently suppressing peaceful protests.
Visitors to the Spirit of Christmas Fair in London have been greeted by Santa Claus warning them that the Fair's owners are involved in the arms trade.
Campaigners have welcomed the government's decision to scrap the controversial Section 44 of the Terrorism Act, which allowed the police to stop and search anyone, without requiring "reasonable suspicion".