In a survey conducted by the housing charity, nearly a quarter of people - the equivalent of 9.9 million adults - said they or someone they know have had to stay living with their partner because they cannot afford to live on their own.
Until recent years, couples with no hope of saving their relationship would expect to live apart after a break up but due to high housing costs more and more people are being forced to remain living together after breaking up.
The figures come from new research undertaken by the charity to examine the way unaffordable housing is changing the way we live.
Kay Boycott, director of policy and campaigns at Shelter said: "Unfortunately relationships do break down which is painful enough, but being forced to carry on living with an ex-partner, even for a short time, must add real pressure to the situation.
"The fact one in four of us either have experienced or know someone that has experienced this situation, means this may be more widespread a problem than we realised."
The research also reveals that high housing costs are often the cause of arguments between couples, and with their families.
Nearly one in six respondents, equivalent to 6.6 million people nationwide, said that worries about housing costs had led to arguments with partners or other members of their family.
Ms Boycott added "As a nation we have accepted the way housing costs have risen hugely over the last few years, but are we ready to accept the human cost this brings?
"We can no longer ignore the massive repercussions our housing crisis is having on individual lives. Tackling the problem must be a priority for all political parties and a key election issue for us all."
