STOP HS2 took part in a Parliamentary lobby day on Monday to try to persuade the coalition to ditch its plans for a high speed line.
Meanwhile councillors in the Vale have voted to lobby the Lib Dem party to delay backing the plans until the full route from London to Scotland is drawn up and assessed.
After the Parliamentary lobby day Penny Gaines, of Quainton, social media director of Stop HS2, wrote an open letter to transport secretary Justine Greening.
She said: “When Stop HS2 was set up in 2010, we adopted the slogan ‘no business case, no environmental case, no money to pay for it’ and since that time organisation after organisation has come out and backed that standpoint.
“The starting point was that it was known that high speed rail was the answer, even before they bothered to ask the question.”
At November’s Aylesbury Liberal Democrat’s annual meeting it was agreed that members would lobby their party to look again at the HS2 proposals and evidence for it.