Tory backbenchers are increasing pressure on Theresa May ahead of crucial votes next week, to make certain that Parliament has the final say on Britain’s future at the end of Brexit negotiations.

Rebels are demanding the Government go further in making clear that MPs and peers will have a vote, not only to approve any deal agreed with the EU, but also to decide whether the UK leaves the bloc with no deal if one cannot be agreed.

On Monday the House of Commons will vote on the matter and Tory backbenchers are saying Ms May must be clearer in her guarantees to give Parliament a say on the final Brexit deal if she wants to avoid an embarrassing defeat.

It comes after the Government’s attempt to avoid a rebellion over plans to increase National Insurance contributions on self-employed people, revealing the difficulty of Ms May’s position in passing controversial legislation with only the slimmest of Commons majorities.

Ex-cabinet minister Nicky Morgan MP told The Independent: “The Government needs to address how Parliament has a say in the event no agreement can be reached with the EU.

“Our constituents will expect us to have a say and that is the bit of the Lords amendment the Government has not yet publicly addressed.”

Ms May is currently trying to pass her Article 50 Bill through Parliament, which when written into law will give her the power to trigger Brexit talks.

She and her ministers had demanded the legislation be passed unapproved, but the House of Lords backed amendments to guarantee the rights of EU citizens living in the UK and to guarantee Parliament a vote on whatever happens at the end of Brexit negotiations.

Europe's chief negotiator Guy Verhofstadt: Britons should keep EU citizenship rights after Brexit

The Labour party, which was behind the so-called “meaningful vote” amendment, is also pushing for greater assurances from the Government.

The Prime Minister had originally said that she would only allow MPs a vote on the terms of the deal she agrees with the EU, and threatened to leave the bloc with no deal if Parliament rejects them.

But concerned Conservative backbenchers said she has to go further. MP Neil Carmichael told The Independent he wanted to hear a clear statement at the despatch box from Brexit Secretary David Davis that Parliament would have a vote in all circumstances. He said that it should be made “without qualification”.

How Brexit affected Britain's favourite foods from Weetabix to Marmite Show all 8 1 /8 How Brexit affected Britain's favourite foods from Weetabix to Marmite How Brexit affected Britain's favourite foods from Weetabix to Marmite Weetabix Chief executive of Weetabix Giles Turrell has warned that the price of one of the nation’s favourite breakfast are likely to go up this year by low-single digits in percentage terms. Reuters How Brexit affected Britain's favourite foods from Weetabix to Marmite Nescafé The cost of a 100g jar of Nescafé Original at Sainsbury’s has gone up 40p from £2.75 to £3.15 – a 14 per cent rise—since the Brexit vote. PA How Brexit affected Britain's favourite foods from Weetabix to Marmite Freddo When contacted by The Independent this month, a Mondelez spokesperson declined to discuss specific brands but confirmed that there would be "selective" price increases across its range despite the American multi-national confectionery giant reporting profits of $548m (£450m) in its last three-month financial period. Mondelez, which bought Cadbury in 2010, said rising commodity costs combined with the slump in the value of the pound had made its products more expensive to make. Cadbury How Brexit affected Britain's favourite foods from Weetabix to Marmite Mr Kipling cakes Premier Foods, the maker of Mr Kipling and Bisto gravy, said that it was considering price rises on a case-by-case basis Reuters How Brexit affected Britain's favourite foods from Weetabix to Marmite Walkers Crisps Walkers, owned by US giant PepsiCo, said "the weakened value of the pound" is affecting the import cost of some of its materials. A Walkers spokesman told the Press Association that a 32g standard bag was set to increase from 50p to 55p, and the larger grab bag from 75p to 80p. Getty How Brexit affected Britain's favourite foods from Weetabix to Marmite Marmite Tesco removed Marmite and other Unilever household brand from its website last October, after the manufacturer tried to raise its prices by about 10 per cent owing to sterling’s slump. Tesco and Unilever resolved their argument, but the price of Marmite has increased in UK supermarkets with the grocer reporting a 250g jar of Marmite will now cost Morrisons’ customers £2.64 - an increase of 12.5 per cent. Rex How Brexit affected Britain's favourite foods from Weetabix to Marmite Toblerone Toblerone came under fire in November after it increased the space between the distinctive triangles of its bars. Mondelez International, the company which makes the product, said the change was made due to price rises in recent months. Pixabay How Brexit affected Britain's favourite foods from Weetabix to Marmite Maltesers Maltesers, billed as the “lighter way to enjoy chocolate”, have also shrunk in size. Mars, which owns the brand, has reduced its pouch weight by 15 per cent. Mars said rising costs mean it had to make the unenviable decision between increasing its prices or reducing the weight of its Malteser packs. iStockphoto

On Thursday in Brussels, Ms May caved in to pressure over the decision to increase NICs, saying the controversial measure would not come in until the autumn and signalled that it could be subject to mitigation, although she was still determined not to say she was backing down on it.

Tory MPs worried that the measure represented a clear breach of an election promise not to increase NICs had just spent 24 hours raising concerns in public.