Labour's Ruth Cadbury said she feared spectators at the Rugby World Cup venue would be subject to smells from the nearby Mogden sewage works.
The Brentford and Isleworth MP said problems persisted despite £140m investment in 2013.
But Thames Water said it was "confident rugby fans will not be turned off Twickenham by odour".
In a statement the company, which manages the sewage works, said its £140m upgrade included the installation of odour-reducing equipment and covers.
It also said it would "continue to work closely" with stadium bosses and Hounslow and Richmond councils in the run-up to the big event.
England Rugby, which manages the west London stadium, declined to comment.
The Rugby World Cup begins on 18 September, with Twickenham stadium hosting some of the major matches.
Environment Minister Rory Stewart initially said a new sewage super storm drain further down the Thames would help, before being corrected by the Brentford and Isleworth MP who said that project was nowhere near the problem site and would not help.
Speaking in the House of Commons, Ms Cadbury said: "There is a real risk the UK could look rather embarrassing if many matches are spoilt by the stench of sewage floating over the stadium."
She called for ministerial intervention, claiming that "storm tanks need covering" and that "dilute sewage keeps discharging into the nearby Thames".
An MP has warned the UK faces "embarrassment" because of a sewage stench pervading Twickenham stadium.