Guardian and Observer readers have raised more than £500,000 for homeless young people and refugees, just 10 days into an annual charity appeal.

The total includes a record £53,000 taken over the phones by Guardian and Observer journalists on Saturday at a telethon.

The 2017 appeal, which runs over the festive period, is raising money for three charities working with vulnerable people on the frontline of homelessness and destitution: Centrepoint, Depaul UK and the No Accommodation Network (Naccom).

Ian Brady, interim chief executive of Depaul UK, said: “This is incredible news. All of us at Depaul would like to thank the kind and supportive Guardian and Observer readers who made Saturday’s telethon such an outstanding success and have given throughout the appeal. Rest assured, your donations will be very well used to help young homeless people.”

Hazel Williams, national director of Naccom, said: “It is wonderful to know that there is such support behind this year’s appeal. On behalf of all our members and the destitute asylum seekers, refugees and migrants they support, we want to say thank you. This money will help to end homelessness for people who have nowhere else to go, and every penny matters.”

Seyi Obakin, chief executive of Centrepoint, said: “£500,000 is a fantastic achievement, and from all of us at Centrepoint I’d like to say a big thank you. I attended the telethon on Saturday and had the privilege of speaking to Guardian and Observer readers. Homeless young people can feel as though they are written off by society – but the response to this appeal demonstrates not only readers’ tremendous generosity but also their belief in the young people we support.”

Journalists who took readers’ callsincluded the Guardian’s editor in chief, Katharine Viner, Polly Toynbee, Owen Jones, Sali Hughes, Simon Hattenstone, Jonathan Freedland, John Crace, Jess Cartner-Morley, Deborah Orr and Decca Aitkenhead.

Launching the appeal, Viner said the campaign was launched in response to the “increasingly visible and distressing” rise in homelessness and destitution in recent years.

She said: “The danger is that we become hardened to the enormity of the presence of rough sleepers huddled in shop doorways, in tents, or on night buses, and unwittingly neglectful of the tens of thousands of hidden homeless squatting on friends’ sofas.”

Centrepoint and Depaul run services aimed at providing shelter and support to homeless 16 to 25 year olds. Naccom represents a network of more than 40 local charities and projects which specialise in housing destitute asylum seekers, refugees and migrants who have no recourse to public funds.

Naccom will use its share of the Guardian and Observer appeal donations to capacity-build the network and support frontline projects via a selective grants process that will be open to its full members.

The 2016 Guardian and Observer charity appeal raised £1.7m for three refugee charities.