Sir David Butler, dubbed the “father of election science”, has died at the age of 98.

The academic, known for inventing the Swingometer and pioneering exit polls, died on Tuesday night, his son confirmed to the PA news agency.

Daniel Butler said his father “seems to have gone through life engendering a great deal of warmth” in his students and admirers.

Tributes have been paid by BBC presenter and former political editor Nick Robinson, the chief executive of BBC News Deborah Turness, pollster Matt Goodwin, Anthony Wells, head of European political and social research at YouGov UK, and shadow secretary of state for trade Nick Thomas-Symonds.

Flags at Nuffield College, where Sir David taught, and New College Oxford, his alma mater, are flying at half-mast to mark his death.

“He was a great father, a loving father,” Daniel Butler added. “We had a very happy childhood growing up in Oxford and he was fun to be a son of.”

He also said that he discovered how “modest” his father was by reading a biography of Butler by journalist and author Michael Crick .

Daniel Butler said the former staple of BBC’s election night coverage would “disclaim his achievements” and did not admit he invented the Swingometer until Sultan of Swing: The Life of David Butler (2018).

The device has become a staple of election coverage and shows the swing visually from one party to another in broadcast news.

His son Ed Butler also told PA: “My father was immensely influential in academic terms.”

He cited his book, Political Change In Britain, written with Donald Stokes, winning the best book in British political studies from 1950 to 2010 award as part of the 60th anniversary celebrations of the Political Studies Association.

Ed Butler added: “My mother and father were also sweet and supportive to my two brothers. They were very good people.”

His biographer Crick, who called Sir David the “father of psephology, or election science”, also spoke on Twitter about how it began.

Crick said: “While still an undergraduate at New College in 1945, Butler started studying election results in terms of percentages, the first step in developing election science.

“He also developed the concept of “swing” as a way to measure British election results.”

Crick said during the 1950 election, when Sir David was aged 25, he became the BBC’s in house analyst for its first election results programme on TV, a job the academic stayed in until 1979.

It was during the 1950s that Sir Winston Churchill had two lengthy meetings with him so the former prime minister could better understand elections.

“Butler also made a huge mark overseas,” he added.

“He was a regular analyst on TV election results programmes in Australia, and also helped Indian TV develop results programmes for the largest democracy in the world.”

BBC News and Current Affairs chief executive Turness paid tribute to Sir David in a statement.

She said he “played a hugely important role in the development and modernising of the BBC’s election coverage” and audiences “looked to him for clear analysis and commentary”.

Presenter Robinson reacted by saying on Twitter: “Sad news. A true great. David Butler was the grand daddy of all election poll watchers, analysts, academics & pundits.”

Sir David retired as a fellow of Nuffield in 1992, the university said, but remained an Emeritus Fellow while he continued to write and speak into his nineties.

He is survived by his two sons, Ed and Daniel, his son Gareth, who worked with him on his books and a radio programme, predeceased him along with his wife Marilyn Evans.

Sir David also has seven grandchildren.