Theresa May is taking her message direct to the opposition.

Days after she danced on stage and promised better times ahead for her Conservative Party members, the U.K. prime minister took the rare step of writing in the Observer newspaper to entice wavering Labour supporters over to her camp.

In an attempt to present her party as the only option for moderate and patriotic voters, she sought to play up her government’s program on house building and managing the nation’s finances, while attacking opposition leader Jeremy Corbyn’s brand of market-unfriendly socialism.

It’s a gamble that could enrage many of the Brexiteer hardliners in her party. The Sunday Times reported that members of the European Reform Group are threatening to vote down government legislation unless May takes a tougher stance against Brussels and stops trying to get support from Labour to get her Brexit plan through.

The newspaper printed a message to the rest of the group from veteran Euroskeptic Bernard Jenkin: “A soft, non-Brexit pushed by the Conservative establishment but put through with Labour support will look like we are abandoning our supporters and remove any sense of obligation among Conservative Brexit-supporting MPs to continue to support the government.”

Chancellor Philip Hammond’s budget at the end of the month is particularly at risk, the report said.

The Sunday Telegraph took a different slant on the ERG’s latest maneuverings. Senior members of the group would support EU officials being stationed at U.K. ports after Brexit to help unlock a Canada-style trade deal with Brussels, the newspaper reported. They could also back the government enforcing EU rules on goods exported to the bloc by the U.K.

Talks between London and Brussels are gathering intensity with time running out to agree to a deal. Bloomberg reported late last week that EU officials are prepared to offer the U.K. a free-trade deal that runs deeper than any previous agreement, but it’s still some way distant from May’s demand for what she calls frictionless trade.