A sense of inevitability has hung over the title race for several weeks but below it, the season is reaching a nerve-jangling climax both in the battle to qualify for next year's Champions League and to stay in the top flight.
City go to White Hart Lane 13 points behind United, who play Aston Villa at Old Trafford on Monday when the title race could be decided.
While City's pride is at stake, the repercussions of Sunday's match are likely to be far more serious for Spurs whose hopes of a top-four finish are under threat from their London rivals.
Andre Villas-Boas's side were in pole position for third place a few weeks ago before defeats by Liverpool and Fulham and a home draw with Everton handed the initiative back to Arsenal and Chelsea.
Arsenal's Saturday kick-off at Fulham means they can apply more pressure before Chelsea go to Liverpool and Spurs play City.
Tottenham's players have had a breather since losing to Basel on penalties in the Europa League, although the break may not have been long enough for Welsh winger Gareth Bale to recover from the ankle injury he sustained in the first leg of the tie.
Arsenal's draw with Everton offered encouragement for Spurs who, according to midfielder Lewis Holtby, face "six cup finals" between now and the end of the season.
"It will be a tremendous game on Sunday," he told Tottenham's website. "City have just reached the final of the FA Cup and these six games are our cup finals.
"They are a side full of quality players but we're determined to get three points, especially at home. It would be a massive win for us."
Sunderland moved three points clear of the relegation zone with a 3-0 win at Newcastle United last weekend - a match memorable for new manager Paolo Di Canio's celebratory knee slide at St James's Park.
