An adviser in British Prime Minister Boris Johnson's office resigned on Monday after online comments resurfaced where he linked intellect to race and seemed to advocate a eugenics policy.
Andrew Sabisky once suggested that black Americans had a lower average intelligence than whites.
Mr Sabisky also said in a 2014 web post that one way to stop unplanned pregnancies "creating a permanent underclass" was to force people to use contraception.
On Monday he said he was in the middle of a "giant character assassination" and was stepping down because he did not want to be a distraction.
"The media hysteria about my old stuff online is mad but I wanted to help Her Majesty's Government, not be a distraction," he said on Twitter.
"Accordingly, I've decided to resign as a contractor."
Mr Sabisky said he hoped the government hired more people with "good geopolitical forecasting track records and that media learn to stop selective quoting".
"If I can't do the work properly there's no point," he said, adding that he had "a lot of other things to do" with his life.
Downing Street had repeatedly refused to say whether Mr Johnson supported the views expressed by Mr Sabisky.
"I'm not going to be commenting on individual appointments," a spokesman said.
The main opposition Labour Party had called for his sacking.
"It's right that Andrew Sabisky is no longer working in government," said party chairman Ian Lavery. "He should never have been appointed in the first place.
Mr Lavery said that Mr Johnson had "serious questions to answer".
The prime minister's chief adviser is Dominic Cummings, 48, who orchestrated the official campaign for Britain to leave the EU.
Writing on Mr Cummings's website in 2014, Mr Sabisky said: "One way to get around the problems of unplanned pregnancies creating a permanent underclass would be to legally enforce universal uptake of long-term contraception at the onset of puberty."
The Cockroach
(Vintage)
Ian McEwan
The specs
Price: From Dh180,000 (estimate)
Engine: 2.0-litre turbocharged and supercharged in-line four-cylinder
Transmission: Eight-speed automatic
Power: 320hp @ 5,700rpm
Torque: 400Nm @ 2,200rpm
Fuel economy, combined: 9.7L / 100km
3%20Body%20Problem
%3Cp%3E%3Cstrong%3ECreators%3A%3C%2Fstrong%3E%20David%20Benioff%2C%20D%20B%20Weiss%2C%20Alexander%20Woo%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3EStarring%3A%20%3C%2Fstrong%3EBenedict%20Wong%2C%20Jess%20Hong%2C%20Jovan%20Adepo%2C%20Eiza%20Gonzalez%2C%20John%20Bradley%2C%20Alex%20Sharp%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3ERating%3A%3C%2Fstrong%3E%203%2F5%3C%2Fp%3E%0A
Ireland (15-1):
Ireland (15-1): Rob Kearney; Keith Earls, Chris Farrell, Bundee Aki, Jacob Stockdale; Jonathan Sexton, Conor Murray; Jack Conan, Sean O'Brien, Peter O'Mahony; James Ryan, Quinn Roux; Tadhg Furlong, Rory Best (capt), Cian Healy
Replacements: Sean Cronin, Dave Kilcoyne, Andrew Porter, Ultan Dillane, Josh van der Flier, John Cooney, Joey Carbery, Jordan Larmour
Coach: Joe Schmidt (NZL)
The%20Letter%20Writer
%3Cp%3E%3Cstrong%3EDirector%3A%3C%2Fstrong%3E%20Layla%20Kaylif%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3EStars%3A%3C%2Fstrong%3E%20Eslam%20Al%20Kawarit%2C%20Rosy%20McEwen%2C%20Muhammad%20Amir%20Nawaz%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3ERating%3A%3C%2Fstrong%3E%202%2F5%3C%2Fp%3E%0A
Jetour T1 specs
Engine: 2-litre turbocharged
Power: 254hp
Torque: 390Nm
Price: From Dh126,000
Available: Now
The%20BaaS%20ecosystem
%3Cp%3EThe%20BaaS%20value%20chain%20consists%20of%20four%20key%20players%3A%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3EConsumers%3A%3C%2Fstrong%3E%20End-users%20of%20the%20financial%20product%20delivered%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3EDistributors%3A%3C%2Fstrong%3E%20Also%20known%20as%20embedders%2C%20these%20are%20the%20firms%20that%20embed%20baking%20services%20directly%20into%20their%20existing%20customer%20journeys%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3EEnablers%3A%3C%2Fstrong%3E%20Usually%20Big%20Tech%20or%20FinTech%20companies%20that%20help%20embed%20financial%20services%20into%20third-party%20platforms%3C%2Fp%3E%0A%3Cp%3E%3Cstrong%3EProviders%3A%3C%2Fstrong%3E%20Financial%20institutions%20holding%20a%20banking%20licence%20and%20offering%20regulated%20products%3C%2Fp%3E%0A
ELIO
Starring: Yonas Kibreab, Zoe Saldana, Brad Garrett
Directors: Madeline Sharafian, Domee Shi, Adrian Molina
Rating: 4/5
GOLF’S RAHMBO
- 5 wins in 22 months as pro
- Three wins in past 10 starts
- 45 pro starts worldwide: 5 wins, 17 top 5s
- Ranked 551th in world on debut, now No 4 (was No 2 earlier this year)
- 5th player in last 30 years to win 3 European Tour and 2 PGA Tour titles before age 24 (Woods, Garcia, McIlroy, Spieth)
Globalization and its Discontents Revisited
Joseph E. Stiglitz
W. W. Norton & Company
Last 10 NBA champions
2017: Golden State bt Cleveland 4-1
2016: Cleveland bt Golden State 4-3
2015: Golden State bt Cleveland 4-2
2014: San Antonio bt Miami 4-1
2013: Miami bt San Antonio 4-3
2012: Miami bt Oklahoma City 4-1
2011: Dallas bt Miami 4-2
2010: Los Angeles Lakers bt Boston 4-3
2009: Los Angeles Lakers bt Orlando 4-1
2008: Boston bt Los Angeles Lakers 4-2