Conservative MP Nadine Dorries says the government’s same-sex marriage bill will take the “sex out of marriage” and wonders whether a sister could marry a sister in order to avoid inheritance tax as part of the reform.

The divorced Mid-Bedfordshire MP, a staunch equal marriage opponent who was reinstated as a Conservative member last week following her six-month suspension for taking part in I’m a Celebrity, Get Me Out of Here, made a series of critical tweets about the Marriage (Same Sex Couples Bill), which faces further debate by MPs on 20 and 21 May.

Warning that the bill could result in the Conservatives losing “as many as fifty seats” at the next general election, the MP cited a Telegraph article by Charles Moore, the paper’s former editor and Lady Thatcher’s official biographer.

Moore wrote: “With gay marriage, the Coalition proposes to alter fundamentally the most important social structure ever known to mankind. If it hopes to slip this quietly past the country over the summer, without any serious consequences, it is being not only dishonest, but stupid.”

Moore then argues that the bill is flawed because it does not stipulate requirements for consummation or divorce.

“The government is introducing, for the first time, a definition of marriage which has no sexual element,” Moore says. “Yet it refuses to face the logical consequence of this surprising innovation. If sexual intercourse is not part of the definition of same-sex marriage, why should blamelessly cohabiting sisters not marry one another in order to avoid inheritance tax? Why should father not marry son?

“Why shouldn’t heterosexual bachelor chum marry heterosexual bachelor chum? What, come to think about it, is so great about the idea of monogamy, once sex and children are removed from the equation? Does the word ‘marriage’ any longer contain much meaning?”

Referencing Moore’s argument on consummation, Nadine Dorries tweeted on Saturday:

“If gay marriage bill takes sex out of marriage could a sister marry a sister to avoid inheritance tax?”

“If David Cameron wants Conservative Party to lose as many as fifty seats at next election he must push forward with the gay marriage bill”.

“If sex is removed from the legal definition of gay marriage, if it can’t take place in a church, what is gay marriage? What defines it?”

“If the answer is love, if legally is only link between gay/straight + marriage is being redefined to accommodate, why do we need marriage?”

“Legal definition of marriage is the basis of the law itself at present it’s based on definition of consummation.”

“Legally, marriage is wholly about sex.”