Sir Elton John has revealed he has plans to become a father again by the end of the year, hoping for a sibling for his for 14-month-old son Zachary.

The singer and his long-term partner David Furnish have reportedly begun their quest to make this happen.

A source told the Scottish Daily Record: “David and Elton have never hidden their desire to extend their family and believe the time is right for another child. By the end of this year, or the beginning of next, there will be a fourth member of the John-Furnish clan.”

The couple, who were civilly partnered in 2005, have been raising Zachary Jackson Levon Furnish-John at their mansion in Windsor, Berkshire. He was born to a surrogate mother in California on Christmas Day 2010. California surrogacy laws – unlike those here in the UK – allow a mother to surrender her claims on a newborn.

Sir Elton, 65, and Furnish, 49, say they both “contributed” to the process and do not know which of them is the biological father – nor do they intend to find out. The couple recently spoke about fears their son will be bullied for having gay parents when he is older.

Furnish said: “We’ve taken advice from counsellors. We’ve also put a whole scrapbook together about his creation, the people who were involved in the process and how the intent was about love. We’re going to raise him to be proud of who he is.”

Sir Elton has described being a parent as “incredible”.