The Prime Minister said Pride Brighton and Hove, which takes place this weekend, was a reminder of why Britain “continues to be recognised as number one in Europe on lesbian, gay, bisexual, and transgender (LGB&T) equality and rights”.
He said it was a “momentous occasion” when the first legal marriages of gay and lesbian couples took place at midnight on 29 March.
Mr Cameron said this weekend’s event was a “fantastic celebration of the LGB&T community and its contribution to the diversity and vibrancy of Brighton and Hove.”
Ed Miliband, the Labour leader, also welcomed the event, but used a video message to warn there is “much more to do” to stamp out homophobia.
He said the Pride event was an opportune moment to reflect on the steps still to be taken.