London's FTSE 100 extended its rally on Monday, led by miners including a jump in iron ore futures, while midcaps relinquished gains after a British lawmaker said "a lot of people" in parliament still opposed Theresa May's EU divorce deal.

While both indexes have risen for the last five sessions on hopes that a potentially disruptive no-deal Brexit would be averted, the FTSE 250 slumped on growing concerns that May's deal would be rejected for the third time by parliament.

The FTSE 100 was up 0.6 percent by 1159 GMT, as global mining giants were lifted by a surge in iron ore futures on supply concerns after Vale's output cuts. That helped it outperform its European counterparts.

However, the more domestically-focused midcap index, which was carried to a five-month high in the last session, dipped 0.4 percent, tracking losses in the pound.

Brexit-backing lawmaker John Redwood said many parliamentarians still opposed Prime Minister Theresa May's deal as their hostility went beyond opposition to the so-called Irish backstop.

Michael Hewson, CMC Markets analyst, said it was unlikely that the parliamentary vote would go through this week and there might be a modest element of profit-taking going on.

"But it is politics, we still remain a while away of pushing this deal through and I think the sell-off in the pound is a little of a reflection of that."

After parliament last week approved a move to delay Brexit beyond March 29, May has just a few days to push her divorce deal through if she wants to go to an EU summit on Thursday with something to offer them in return for more time.

News-related moves were scant but buyout bids boosted banks.

Helping the main bourse were miners that advanced 2.3 percent to be on course for their best day since late January. Anglo American, Rio Tinto and BHP  all gained nearly 2 percent.

German giants Deutsche Bank and Commerzbank  confirming that they were in talks about a merger boosted financial stocks to levels not seen since last October.

In the broader financial sector, London-listed shares in payment processor Worldpay also surged 10.7 percent after the UK-based group agreed to be bought over by U.S. fintech group Fidelity National Information Services for about $35 billion.

Bank stocks are also on a six-day winning streak with a no-deal Brexit on March 29 seemingly off the table.

Footasylum shot up 74.2 percent to 81 pence, inching near the 82.5 pence a share offered by larger JD Sports  for the sportswear retailer.

Oilfield services provider Hunting added 4.2 percent on the FTSE 250 index after UBS hiked its rating on stock.