Singh wrote in Hindi that as there are three chief ministerial contenders in the Bharatiya Janata Party (BJP), he was confused whom should he write to. "I am writing to you as you are the seniormost and most experienced."
The Aam Aadmi Party (AAP) leader said that the people of the national capital want to ask three questions from the BJP.
"Does BJP support free electricity up to 200 units for people of Delhi? Does BJP support waiver of arrears in water bills for people of Delhi?, and who will be BJP's chief ministerial face in Delhi?"
Singh said wherever he goes, people ask these questions and "the BJP has a habit of either ignoring the questions or not giving clear answers".
The AAP leader said he expects an answer in 24 hours from Goel.
He also accused Goel and his workers of manhandling AAP leader Dilip Pandey when he went to one of the public meetings organised by the senior BJP leader.
"Pandey had asked Goel if he supports the Delhi government's announcement of providing free water and electricity to the people. Instead of answering the questions, Goel and his supporters manhandled Pandey and his team," Singh said.
On Wednesday, Singh had said there was serious infighting in the Delhi BJP and that three leaders Goel, BJP Delhi unit chief Manoj Tiwari and Leader of Opposition Vijendra Gupta are all vying to take credit.
( With inputs from IANS )