Britain needs a serious debate about our head of state as we fast approach the succession of King Charles.  That's the message from a republican movement that is feeling bullish about its prospects over the next decade.

The campaign group Republic has been steadily growing in strength in recent years, taking on members, better resourced and better equipped to challenge the monarchy.

The group's CEO, Graham Smith, said today:

"Headline polling figures mask what's really happening: a growing indifference to the royals, a greater sense of citizenship and disillusionment with the political system - and an active, organised republicanism that is increasingly clear about the way ahead."

"We can also see a loosening of support for monarchies in Europe and the Commonwealth.  When one falls others will follow and that will change the debate here in the UK."

"Crucially, organised republicanism is now better organised than ever before.  We know we have our work cut out, but we're travelling in the right direction and at good speed."

"The Queen's birthday reminds us that support for the monarchy is bound up with support for the Queen."

"In a hereditary monarchy the Queen's age becomes a political issue. Long before the Queen dies the country will need to debate what happens next."

"With the republican movement stronger than ever - and growing - and with the succession looming on the horizon, the monarchy is in a more perilous position than pundits will tell you this week."