Carshalton and Wallington MP Tom Brake has backed a call for defibrillators to be introduced in schools, sports centres and other public places.
Mr Brake said the defibrillators, which are used to shock a heart back into life after it stops, could make the difference between life and death if they are widely available.
He has given his backing to the Oliver King foundation, set up by a father whose son died following a cardiac arrest at a swimming pool.
Mark King believes Oliver, 12, would have survived if there had been a defibrillator at the poolside.
Mr Brake said: "The time between a person suffering a cardiac arrest and a paramedic arriving with a defibrillator can, and tragically has, made the difference between life and death.
"If we can reduce this wait and increase the chance of survival then we must."
For more information on the Oliver King Foundation, visit www.theoliverkingfoundation.co.uk.